Obviously this is something that'll be worked on as the game moves forward, but I want to chime in, too and say that the beta is quite sluggish on my laptop.  On the cloth map my FPS is fine, but zoomed in it drops to the 10-15 range, which is surprisingly slow given that I'm running it with about as low graphics as I can.  I don't have the most powerful graphics card in the world (what with this being a laptop and all), but it runs, for example, Dragon Age Origins without that kind of slowdown.

Specs:

Windows 7 Home Premium, 64-bit

Intel Core 2 Duo CPU P9600, both @ 2.67Ghz

4.00 GB Ram

NVidia GeForce 9300M GS

The only thing I notice is that sovereign movement is super sticky, since beta 1, but I'm sure that it will clear up later, the transitions from cloth to 3d to max zoom are really nice the close up zoom feature over the functions of your town are reminiscent of populous.

Yeah, I'm seeing a huge stutter when the selected character finishes pathing in 2A that I don't remember seeing in the last beta.  It doesn't happen every time (probably every ~3-5 turns of continuous movement).  It's accompanied by drop of ~20+ FPS  (from an at-rest FPS of 30-90, depending on what's visible).  Non-stutter paths usually end with a drop of ~10 FPS, but I've seen a drop from ~35 to single-digit FPS (in which everything freezes for half a second).  This is with Auto Turn enabled (so the stutter probably includes all of the end-of-turn calculations).

In Beta 2, I wasn't really watching FPS during movement, so I can't compare the exact numbers.  In general, movement seemed smoother in Beta 2 than in 2A.

Same machine for both betas:
Win 7 x64
4GB ram
Core 2 X9650 @3GHz (quad)
Nvidia GTX 260 (no sli)

Yes performance is noticeably worse with 2a on my system as well, with zoom/scroll & character anim all choppier.

Win 7 x64, 6gb ram, i7 930, Radeon 5870

I don't really think so, I would not expect performance to be very good until much closer to release... As they enable things, like the full graphics, they will be able to get more reports and information on where they are having performance problems and so on...

Talking about comparative performance between the two beta2 releases here, using the same settings.

I was/am running 2560x1600 using 2x anti-aliasing; beta2 was pretty smooth at these settings, beta2a less so.

I would like to echo the sentiment that Beta 2 ran much smoother than Beta 2B (using the same settings).  Not only that, I think Beta 2 had fewer crashes/freeze-ups as well.