1) Most of your diving is shallower than 120ft
2) You want the warm air factor
3) You philosophically don't want the eCCR over the mCCR
4) you want to dive 2-3 hr profiles and wont be trashing 2 lbs of sorb a day.
Number three is the only one I think that really holds up over the Chop, at least if you use EACs.