I have had Onkyo as well as Yamaha and Dennon, can't go wrong with them they are good solid amps but Onkyo are my fav.
Don't know about 9.2 though, talk about overkill. Most peoples home theatres aren't even set up to run 7.1 properly let alone 9.2. My amp is capable of running 7.2 but seeing as I don't need another sub and don't have at least 3-4 feet behind me to run proper 7.1 so I just use 5.1 and it's fine.