I own an xpa 5 and it is MUCH louder than the Denon 130w avr I have in my bedroom {I had it in the parlor at one point}, but the more important fact is, it just sounds better, more relaxed and effortless... Not sure what the test results say, but definetly makes a difference to my ears.. One more thing is after playing expendables nice and loud {just pushing a pair of bookshelfs and a center, no surrounds} my Denon is pretty Hot... After playing tv all day at low level, and then watching 2 back to back movies at a loud level, the XPA may as well have been off the entire time, maybe 5 degrees warmer than ambient.... Not sure if the graphs and charts and spec numbers everybody refers to show that...
Also I had my Denon {which dont get me wrong does its job} repaired once already and was a refurb when I bought it compared to the xpa 5 which I haven't had as long but has much more use on it {that is on from 7a-10p everyday vs the denon is on from 10p-12p ,auto off at midnight}... Plus the denon only gets played loud once and a while, the xpa5 is in my living room and gets the sharp end of abuse, between earth shaking video games to loud music from the kids {cable box music at that}, ect... I dont know how its not a melted pile of caps and copper...
but anyway, I know their are a ton of people on here that have a lot against separates, and swear by just getting an avr and calling it good, but try an amp out, and when your avr is trashed or out of date, buy yourself a processor only or a inexpensive avr with preouts and dont worry about how many channels that 220 watts is getting split off to, or how low your speakers impede drops.... because you will have plenty.....
One more thing, I have seen some pretty nice HT setups, from homes to store listening rooms and anything really nice always has a separate amp... {I just bid a job for a gentleman who owns a half dozen dunkin donuts, and snuck a peak at his HT, that he spent $50K on, he has 9 amps, not sure how its setup, but he has 2 custom built hidden subs, with Thiel speakers {I knew what company installed it as soon as I seen them

}... But anyway I never seen a set of $10K speakers hooked to just an avr with no separate amps..
Granted if you have a small/medium room and watch what speakers you run, I know most avr's will be fine... but as soon as the rooms get larger and the speakers get harder to run, with louder materiel, that smell you notice is a mix of the epoxy they stuck in their and the various plastics and paints they use getting heated up

....