Jack, have you played DW? I thought it was an IGOUGO TBS game, but it is pausable RTS. Is that 'the same' as an IGOUGO game (i.e.-just pause after the PC's turn? Do you have any experience with pausable RTS games? I think I don't like RTS (I never really played one, to be honest).
I do have it and all the expansions, and it is a great game in certain aspects, and annoying in others. It is a pausable RTS, but I really hesitate to put it in the same category as other "4x RTS" games like Sins of a Solar Empire. There are no turns, everything is simultaneous and there are no separate battle instances (like Sins), but where they differ is that Distant Worlds' pace is much slower. It is also many orders of magnitude more complex. Imagine Sins, but instead of single planets per system, solar systems with up to 50 habitable planets and moons. Then times the number of systems in an average Sins game by 100. Now combine that with an economy that doesn't use a shared pool of resources like Sins does, but every planet, star base and outpost has it's own stockpile of resources. Now imagine instead of 3 resources like in Sins, add 50 different types, and each type has a specific use in weapons, shields, engines, etc.
The good news is that the game has a very good automation system that you can pick and choose what areas you have manual control over. The AI does a really good job in it's automated abilities too. If you like, you can slowly wean yourself off of the auto control, but I'd say that's for "power users" only, or maybe for users that have been playing the game for a year. Distant Worlds allows you to focus on the areas you like best about managing a space empire. You can turn everything off except fleet control, and pretend to be a fleet admiral, defending your borders from pirates and space monsters.
It's a great game, and the sheer level of depth and replayability is amazing... but be prepared for a brick wall of a learning curve. The only gaming experience I can even closely compare it to would be Dominions 3. At first it will seem a bit overwhelming, but as you ease into it, it can be one of the best 4x experiences out there.