Worth it?

I bought it and I would say its worth buying (very entertaining and somewhat addicting)    not to mention the standalone expansion that will come out this summer will be at a discount... but ultimately its up to you.

Nope, wait for the expansion, that one will be worth it.

Well it tends to bore me.  The tactical battles (combat) I find rather bland.  The whole games seems more like a Total War game with some large differences, and minor grievances than say Civ or MOO or AoW or MoM.  One thing to keep in mind though is a budget for a TW game versus the budget for Elemental.  I suspect there is a large difference.

Items I find in common:

1. Dynasties
2. Advisors/Generals as units
3. Tatcial Battles
4. Diplomacy
5. City Management
6. Empire Management
7. Explore, Expand, and Conquer Gameplay

Things I find different with Elemental (not cosidering art or sound)

1. High Fantasy
2. The Sovereign (thoe the TW series had kings/leaders, but their function was very dynasty related and really a character)
3. Magic (that high fantasy thing)
4. More Open.  It's a sandbox game.  No turn limits (though I think you can add one).  You win buy achieving a goal but not with in X amount of time (yeah - I hate time limits)
5. Much more Mod friendly.  It even comes with some basic mod tools for you play with.

My minor (mostly) Grievances:

1. Dynasties don't feel very alive or fleshed out.  They just sort of exist.  The characters and dynasties for the TW games feels more more beefy.  In TW they had a ton of traits from personality, leadership, war, production, etc.  
2. Trade in Elemntal is very basic.  You just move a caravan around and create a link.  No trade Items like you establish in TW or really Civ, though resource trading matches Civ more.   Caravans also need a bit of babysitting since in Elemental, they are actual units moving between trade points and can be attack.  Wandering monsters are a bit of a pain.
3. Diplomacy doesn't feel right.  You accumulate policital capital like currency and spend it as such.  It's like you have a vault full of Diplomacy Coins in addition to the Gildar vault.  I guess diplomacy feels like a banking game than diplomacy.
4. Combat is extremely boring.  I'd say it can't hold a candle to TW, is not like AoW or even MoM.   There isn't any siege interface either.  City combat is like field combat except the defenders have more HP's based on the cities defenses.  It's very basic in my opinion.   I'd describe it as GalCiv II with an appearnce of trying to pull off a tactile battlefield.
5. The terrain really isn't very interesting to explore.  Even when you get techs that cause ruins and caches, etc. to appear, it's rather ho-hum.  The way things are clumped and just kind of appear.  Often time major things will appear right outside major cities.  For me this makes the map feel constrained and non-adventurous.  I don't feel like I'm conquering the wilderness or bringing life/safety, etc after the cataclysm.
6. The way cities grow and mange bothers me.  Like many games, you research tech, and add buildings.  Unlike TW, you have the option of where to place them and watch the city grow.  Over all, placement is meanless unless there is a resource that requires a building on top to use.  Drives me nuts, but I think this folds back into tactical battle with no real siege component.  You place cities where you wish though as long as they aren't within X radius of another city. 
7. Also, the way cities grow irritates me.  As an example, I would expect a series of farming (or resource) villages and towns with fields surrounding my trade/defense/industry hub cities, but it doesn't work like this.  A field is just another building in the city.  You can't farm in general.  You need a resource to grow food even though the land seems to support grass, trees, etc.  Though you can build a garden after some mid-high tech (I would think is a basic structure for a, "peasant,") and it is also just another building.  You also can't log.  You specifically have to have an old growth resource to log.  No starting towns or, "colonies," around a forest to provide the basic building materials for housing, etc.  Forests are primarily for show, though new we can at least clear them.  I can't remember if they provide any materials when you do, but it costs you money.  Also there is this idea that prestige gains citizens, not jobs, tax rates, safety, or resources/fertile land.  In case you can't tell I have a big problem with city management/growth.
8. So far, little to no naval aspect.  There is a harbor, which doesn't affect trade, fishing, etc.  It's just there for a transport which I have never found a use for.

Now I probably come across as rather negative.  I don't necessarily mean to.  There are things I like.  The music, and at times the art.  I seem to be able to play my sovereign as I like - magic versus a melee centric sovereign.  I like the open sandbox approach.  Elemental has a lot of basics to play with.  I just find the items present basic.  There is a huge amount of background material and even a book written by Frogboy it's just that these items really don't seem to touch the game beyond a name drop now and again.  Note also, dungeons, adventure, and treasure chests aren't really dungeons.  You move over one on the global map, and it may drop you into a, "tactical," battle, otherwise it's just a one shot resource node.  Like a goody hut in Civ.  Those are some of my present opinions any way.

I would wait and see how the first expansion is received. It's a stand-alone game, so no reason to purchase E:WoM before it.

While E:WoM has come a long way since it's release, it's still not near other Stardock games in quality.

Funny actually I would say it's much higher quality than the usual Stardock game. Meaning that it is an attempt to get into a different league than the usual  "fun but low budget strategy game" (at least that's the perception I have always had of Stardock games).

Problem is that it is just not quite there yet. It will be eventually (unless they run out of money while trying)

I guess it's a matter of defining what 'quality' means for each of us. I definitely agree with you that Elemental is aiming high, although I wouldn't call the final Galciv II as lacking in depth either.

For me, quality means the level of enjoyment I'm getting from the game, all things considered. I've got two machines I use regularly, one regular laptop and the other a high-end tabletop PC. Even with the latest patch, I haven't been able to complete 30 turns on my laptop without crashing. And the high-end tabletop is suffering from serious UI slowdowns which are not there on the laptop.

Technical issues aside, like you said, the game just isn't quite there yet in other aspects either.

Can't play well due to technical problems + other aspects lacking = quality? Not for me. It may be in the future, but not right now. Hence my words "it's still not near other Stardock games in quality".

I have played this game in it's many versions since release, and feel that I have a good understanding for the overall "feel" of the game.

The city building and research part of the game feel fine to me, especially due to the bonuses given to cities based on their size and the constraint of dealing with food as a limiter to empire/kingdom size.  There aren't enough spells yet, and the fact that you have access to research every spell of a given spellbook at your current spell level makes for a "rut" like research tree.  If the spells you could research were more randomized like MoM or techs in MoO, it would be a little fresher and more challenging.  The tactical AI is simply not fair to the AI opponents, and if you want to play the game fairly against the AI opponents, you should "auto resolve" all battles, otherwise you will annihilate the AI in tactical battles every time.  I have only been able to play on small or medium maps, so by the time the Ai and I have to fight for space, they normally have not produced units in groups of four.  My grouped units easily outlast the stronger but individual AI units, making taking over the AI cities nothing more than a grind.  The only magic the AI uses against me ( including the 1.19c build ) are embedded magical attacks in summoned units like the Demons attack. I still haven't faced AI archers unless it's a hired brigand or a hero equipped with a bow, despite how powerful they could be against my units sitting and waiting for the AI to bring itself into melee attack range.

I'm still waiting for the game to live up to what it's hiergammon alludes it is capable of.  Maybe that will occur in patched versions here, or maybe that will occur in the add-ons, I'm not really sure which it will be.

No. Wait to see how the expansion turns out first.