I have the 3806 hooked to the M60's and I could not be happier. IMHO, it sounds better than the Yamaha HTR-5890 I was using before this.
No problems, no complaints.
I cannot compare it to the Pioneer. But then again, the receivers are very comparible. Maybe receiver features can help you decide... the Pioneer has video scaling and dedicated iPod port, the Denon does not.