There are some who find limitations with the XPA series, and I am one of those. In my 2 channel system the XPA-3(one channel idle) running Paradigm Signature S6 speakers, the XPA was harsh at higher volumes. I had the amp for 3 years with an XDA-1 and ERC-1. I finally tried a Parasound A21 amp. Better in several ways and no harshness at levels above 82db as the XPA amp was.
I'm not sure if I could have softened the sound with cables or something else, but at the end of the day, I prefer the Parasound greatly with my speakers.
I read with interest when they came out with the 2nd generation editions, billed as "all new inside and out". But when I carefully compared the specs of the new vs old, the power supplies and caps were the same, and the power ratings were the same. They changed the cosmetics and the RCA connects in back, but they are hardly new on the inside. I was disappointed with this, as I thought this was a great opportunity for Emotiva to evolve the models with performance and SQ improvements as many brands do. The XPA-5 actually lost some weight for some reason.
Anyway, they are a decent amp for the money spent, but one can do better. If money is your main consideration, Emotiva is the price beater.