I watched the Rank 1 in solo matchmaking play some games last night (a couple hours). It seems a lot of the claims of the reviewers and players I've read *were* unfounded.
The game is indeed more slow paced than say Starcraft 2, but it's still pretty action packed. It seems from minute one scouts are being sent across the map and small skirmishes escalate into larger engagements which eventually decide the game. Since there is effectively only one resource IN the game, controlling that resource is of extreme importance. The engagements themselves seemed pretty interesting, with micro playing a decent role but not an absolute one. Obviously this rank 1 player (tag Bikerush, an old Zero Hour vet) had SC2 level micro, but then again he's the best player in the entire game currently.
The game itself looked like a lot of fun. A nice balance between constant action while keeping micro as minimal as possible (though once again, still incredibly important). It did turn out to be true that the humans and the beta were indeed quite different in practice, even if their units functioned somewhat similarly. The only major problems I saw with the game were that, at this point, the humans seem a bit underpowered compared to the other two. Everytime I saw a human played (which was rarely) they got absolutely crushed. It just didn't seem like they could keep up with the production of the other two races and their defenses just weren't strong enough to develop enough of a foothold on the map to matter.
The graphics were another matter. This streamer, who I'm sure had a top of the line computer, had to put all the settings on low just to stream it, and even still there were visible hiccups and even total moments of screen freezing for several seconds during the bigger engagements.
Finally, the low variety of units did seem like it would get old after awhile, though it seems they went with the Blizzard "minimalist" approach to balancing, which does typically work better, and to those who have an interest in competitive play, I highly doubt the lack of units will much matter. Hopefully some future expansions can spice things up.
In terms of the uselessness of the Goo's "god tier" unit, which I haven't yet seen, one would hope that a future balance patch could fix that quite nicely.
All in all, looks like an incredibly fun game and definitely an important addition to the RTS genre. Still not willing to pay $50 but I might go with $40 or so if it goes on sale.