well it also depends on the quality of reciever you have as well (referring to if he should upgrade his 100x5 reciever). Like car audio....not all components are made equal. A 70x5 denon will play cleaner and be more powerful than a 100x5 RCA,sony,pioneer,sherwood,kenwood,aiwa,teak,etc.
In my opinion Denon is the best reciever for the money right now...and with that said I have a harman kardon. But Denon, Harman, Yamaha (the good stuff, not BB), and onkyo (sp?) are all pretty good recievers.
