so i have been to both MHSSC and COC so i will provide insite on those camps.
MHSSC is good because it is cheap, has decent food,  and is chill. You get to ride both MHSSC park (hike park) and timberline public park. its very chill and gives you the small camp vibe. although it is small they still have awesome coaches.
The downside to MHSSC is it is a camp with its primary focus on racing. so basically you wake up really early because the racers want the hard snow. when i went we ended up just sitting around for between 1-2 and even then it was too early for the park to be open.
MHSSC is also obviously on Mt.Hood which is far different than whistler. you have to take buses up to the mountain from the camps and i find the snow is of poorer quality than whistler (still awesome dont get me wrong)
So COC. COC is a good camp in some aspects and bad in others. You get some decent stuff on giveaway and get to ride the COC park and whis pub park all while staying in a hotel room where you walk to the lift which takes you to the glacier ( a feature i like). COC has a bit of a price tag so what i did was go for the camp with all the food, hospitality, etc but no coaching. i was a fan of this because i did not need to like follow a group around, i could just decide what i wanted to do and ride what park i wanted to.
The downside of COC is that the park is much smaller than you expect. the huge 80 feature park you see in some videos is no more because racers have taken over all the glacier space. If you go to COC and expect a huge park you will think they have gone on welfare.
As far as momentum goes i think it looks sweet. The park this year (summer 2014) looked much better than the COC park and also had more of a creative aspect. i think it would be a better camp because you go to different restaraunts every night (it is the same restaurant every night at COC) but of course these luxuries are reflected in the prices. the only thing that bugs me about momentum is when people say that it is so much better than COC for the fact that it has a private tow. This is stupid to say because when i was there, the private tow was equally or more busy than the public one, making it no advantage. i think private is a loose term too because im am pretty certain the tow was shared with moguls and a race camp.
All in all, both COC and MHSSC are good camps, you will have fun at either, it just depends on what you are looking for!