I promised a review of Cardrunners.com and so here it is (I know its a bit late, but I havent really been at home much lately, I've been really bussy). Note that I'm reviewing CR solely on its NL cashgame content (my focuspoint is NL100 6-max, because thats what I am playing myself).

Cardrunners review

When signing up to CR (Cardrunners) you get access to several features: a poker forum much like 2+2 and FTR, articles written by CR pros, blogs from the pros and of course the instructional videos.

The CR forum is build up much like FTR and 2+2 and its moderated by the CR pros. To be honest I didnt really find the boards that interesting, the activity and content isnt as good as FTR and 2+2, so I think you'll be better off using your limited sparetime reading FTR and 2+2 instead (or watching the CR videos).
CR also have instructional articles. For the time I was signed up I actually never got to read more than one article. I dont think that the articles has a whole lot to offer to a average player like myself compared to all the good posts on FTR and 2+2.
I'm not saying that you cant be pick something from the CR boards and articles, but they shouldnt be why you join CR.

The instructional videos are the bread and butter of cardrunners. There are videos both for cash games, SnGs and MTTs. The cash game videos are mainly by Green Plastic (plays up to NL 50/100 online) and muddywater (I think he plays mainly NL 10/20 online).
Green plastic plays a LAG style while muddywater plays a more TAG style. I'm playing mainly TAG myself, so when I used to hear that Green plastic was playing LAG in his videos, I thought that they wouldnt be anything worth to me - I was wrong. What you learn from the instructional videos is how to think at the tables. For example Green Plastic mostly explains why he is folding/calling/raising in a certain hand and he explains the logic behind his reasoning. The things you learn from GP's videos is not that raising JTs UTG is a thing you should do because he does it (because he plays LAGG) - but what you learn is how to think correctly at the poker table, how to think a hand through and decide on the best play on a given street. I especially like when he faces a big turn or river bet in his videos and he has to decide between calling or folding - in these situations he explains what kind of hands he can put his opponent on and wether that should lead to him calling or folding. This is a good way to learn better hand reading, which is IMO the single most important skill in NLHE (by far). Already there you can pick up a whole lot from GPs videos (unless you are already an experienced hand reader).
While I was signed up at CR I only got to watch two videos by muddywater, but he seemed like he played a very standard TAG style. I liked his videos as well (much of the comments above on GPs videos apply to muddywaters videos as well) although his commentary wasnt as good as GPs. I'll imagine that watching his videos will help improve your standard ABC tag game.
There are videos for all kinds of limits (mainly NL100 and upwards, but there are a couple of NL25 and NL50 videos aswell), and although NL2000 plays very differently from NL100 I still believe you can learn alot and improve your own game by watching videos from high stakes although you still play small stakes.

Finally you also get access to blogs written by the CR pros. I dont think these have much poker content, but I actually found them a good read, so I like them as an added bonus to the instructional videos.

Conclusion
The CR videos wont automaticly make you a better poker player. But if you are able to absorb the logic behind GPs and muddywaters plays in the videos and apply it to your own play at the tables, then you'll be able to pick up a great deal. If you are a serious student of this game, and you want to improve your thinking at the tables and maybe learn a move or two, then I think you should seriously consider giving CR a try (especially if you are playing NL100 with a proper BR, because the the signup fee for one month is less than a buyin, and if you play a lot you will get your fee back plus more if you just pick up a thing or two from the videos).