GG Kumo vs ULA CDT

"Essentially I'm looking for the most comfortable " Comfort in a frameless pack has a lot to do with how your pack it. Filling in any gaps to make everything more rigid in the pack really helps due to the lack of frame. With any frameless pack, you need to watch your maximum total weight as above mid 20's for more then a short period may cause some comfort issues. I've been very happy with the CDT but my baseweight is 8-10.5 lbs.

Unless you go to the annual ADZPCTKO event near San Diego where both vendors participate, its going to be hard to find someone whose used both. ULA has a good return policy if you don't like it (just pay for return shipping). If GG will take back an unused pack, then you might consider buying both and see how they feel at home loaded up.