I bought the OS32 Kriega soft bags with the SW-Motech Pro Side-Carrier. The rack comes off in about 2 minutes leaving just small parts on the bike (if you wanted to). The Kriega have plates that allow to attache different bags, a rotopax, etc.
My only problem is on the exhaust side the rack touches the exhaust, and its hard to align the holes to install that side. Waiting to hear back from where I bought it from to see whats up with that. Once I have a right side that fits properly, I'll be pretty happy with the setup. I've gone back and forth on the idea of hard vs soft panniers...and for a few reasons, I went with the soft bags: if you drop the bike it absorbs the impact, offroad you are less likely to have your alu boxes break your leg in a fall, you can expand or shrink it a bit depending on the load you carry as opposed to always taking maximum space even when empty.
Price wise, it's not much cheaper than hard cases. Also bought a Sw-motech rear rack so I can install a kriega bag on the top (which also serves as a small back support for my gf).