I normally shoot an O/U, but I also have A400 Xtreme with the kick off system. Cracking gun, hardly any felt recoil due to the kick off. Have shot sporting with it, but never skeet. I've never put anything smaller than 28g and 70mm length and, so far, never had a jam.
A few others in my shooting circle have A400 variants, and they also rate them. Bought it primarily as a proper wet weather gun, but I'd be happy shooting it for a registered ESP shoot.