I have not heard of any quirks, but I did research these alot last year, and received two particular comments many times.
1. You have to use high quality mags with these rifles. Otherwise, they will jam. (no real surprise). So, forget buying aftermarket junk mags or used mags.
2. You have to really work the action back and forth briskly, with a good "snap", or otherwise they will jam. No problem doing this standing up, but if you are trying to shoot prone, then it really takes some practice and technique. This is what steered me away from these rifles.
Hope this info helps.
Mannyrock