from the FAQ:
Q: How do I use my sleeping pad in conjunction with the Ohm? What pads work the best?
A: Just about any lightweight pad (foam or inflatable) will work as a 'frame' inside the Ohm. 3/4 and full length pads that can be folded (as opposed to rolled) work the best. If you are using an inflatable mattress, deflate, then fold it into 1/3's or 1/5's before inserting.
I have a circuit too, and I have used it in every possible configuration, no stays, carbon fiber stays, all stays, no CCF pad, with CCF pad, and combinations therein. I judge what supports the weight the best, and when it starts to drop onto shoulders and cannot keep angle on load lifters. Without a CCF pad, and without the Al stay, forget it. The carbon fiber stay alone doesnt work well past 15-20 lbs. There is plenty of sagging so that the top of the straps drops below top of shoulders, and load lifter angle is reduced to almost none with only 25 lbs.
The ohm is the same way.
From pictures Ive seen here, and on reviews, and blogs, theres a lot of folks who dont know how their pack should fit and be worn. Load lifter straps that are horizontal, shoulder straps that start below shoulder and wrap over, and hip belts worn low around hips or below, not across the crest. This is not the way the pack is supposed to be worn. That is the way many wear them because it is obviously not supporting the load properly, and most all the weight is riding on the shoulders.
In my experience, without a CCF pad inside, there is definitely way more sagging unless the Al stay is used too. The fabric alone is not rigid between the carbon fiber stays and the hipbelt velcro attachment. It is fairly rigid when the pack is packed with a CCF against the backpanel though. The hip belt stabilizers dont support anything, but if you look and they are angled downward to the rear, its because the pack is SAGGING