For sure it wouldn't be my first pick (not by a longshot).
As far as the software being draining on computer & experiencing freezeout problems,... I've never experienced anything of the sort (with multiple tables opened & while playing on 3 or 4 other sites at the same time as Carbon). This was on a laptop with 1GB Ram, another with 2GB, & another with 4GB. It ran fine on all of them, never ever have had a problem (zero freezeups, etc.).
I play on ~half-dozen sites and of those, Carbon would rank in #7. idk.. I just don't like it.
If you were playing micro buyin SNG's I think it'd be a decent place to play as the players seemed pretty weak on there in comparsion to say Fulltilt for example (although the $1's & $2's (and sometimes $5's, depending upon time of day) can be pretty bad too). I don't think it'd be too difficult to maintain a small
bankroll on Carbon by playing the micro limits.
As a suggestion, why not try out some freerolls on there first, just to see whether or not you like it. If you get over 65posts (or however many it is atm... is it 65?.. or 75??) then you'll be able to play in the Cardschat freeroll on there.
As mentioned above, most of the tournaments on Carbon have a pretty fast structure to them - - once the blinds begin to go up, they REALLY GO UP, so that even when you might be a ways off the bubble, stack sizes are so shallow that even the avg. stack size should be playing shove/fold poker. It's a bit too fast for my liking.