For greater than 5 meters I would say try it and see. Depends on your application how it would be affected, but electrical signals travel at the speed of light so it won't lag just based on the distance.
not sure about degradation. i own 2 of these and have plugged them together along with other branded usb extensions that are shorter (3'-6' specifically) for 24'+ total length, and have had no issues. I used it to shoot tethered with my 40d and 5d DSLRs.
Ive also used any combination of different cables to charge and play with ps3 controllers.