What follows is a stream of consciousness discussion with myself over some different stock options for my Bushmaster ORC 308 (I'm not crazy, I just have a blog).
Weight: ~0.45 lbs
Slightly rattle-y, black, sling mount catches on things (like your breast pocket and such). Works ok, but definitely upgradeable.
Weight: 0.53 lbs
Reviewers mostly seem to say that this one locks up nice and tight, and to not waste your money on a CTR.
Weight: 0.58 lbs
Has two locking bits for extra... lockiness. Reviewers seem to say that this is the best... stock... evahr! and they wouldn't think about buying any other.
Weight: 0.78 lbs
Same double locking system as the CTR, but now with added storage compartment. I like the idea of the storage compartment, but I am not sure what you would store in it. Extra springs and parts? Why wouldn't you just keep that stuff separate rather than carrying it around with you all the time? I'm not planning on tons of field abuse--though I suppose the zombie uprising could happen at any time and it's good to plan for the worst. Is the extra weight of it going to be something annoying, or will it not be noticeable?
There is also the regular ACS, which has battery storage tubes on the sides. Weighs and costs more, I don't like the size of it with the extra bulk, and I don't think I need to carry around 6 batteries all the time.
So, to sum up, leaning toward the MOE, or maybe the ACS-L (though I am not sure if the latter has been released yet--Midway has a "out of stock, back in stock by 12-30-11" message, and everywhere else seems to be similar). So yeah, gunundrums.