Yeah, resource management (cards, action points and soulstones) makes for a VERY interesting dynamic--different enough from Warmachine/Hordes to give it a unique flavor but similar in notion that if you've played those games, you have a sense as to how it works.
The only complaint I've heard (and this is mostly for the newer figs) is that the game is getting a little special-rules happy, but I suspect a lot of those will be FAQed out (Wyrd has been pretty good on that). It's definitely worth checking the FAQ out as some rules have gone through subtle but important revisions (example: the Ronin's Run Through ability went from costing 1 ap to 2 ap--a seemingly small but very important difference, as it takes the figures from stupid broken to just very good).
The only other 'down side' is that because the number of figures per side is so small (as many as 10 figures, maybe) it's easy to go off the deep end and get a whole bunch of factions/warbands. I'm up to 3 arcanist warbands, 1 outcast warband, and I've got 3 more waiting to hit the painting table...