I love my 4311. I just upgraded my speakers (RF-7iis, RC-64ii, RB-51iis) and the 4311 runs them just fine. I love the airplay feature and use it often. I am also a fan of the GUI, web control features, settings save/load, and Audyssey xt32.
If you have not already, make sure to read Batpig's guide: http://batpigworld.com/
Also, there are some very knowledgeable people that frequent the 4311 forum on AVS if you run into trouble.