I've had my AVR-3806 for 2.5 months now (got it Dec. '05), and overall I'm pleased with the unit. The sound quality is great, and there are plenty of features that suit all my current needs in a prepro/receiver.
I mention pre/pro cause I'm using an external amp to power my center channel to help take some strain off the 3806's amp. Although rated at 120wpc x7 channels, pushing all of the channels at once when playing something such as an intense surround audio DVD (Blue Man Group's first DVD Audio for example) puts the 3806 in a strain if you like loud levels (I only occasionally do...). I put an old Parasound 2 channel amp I had into bridged mono mode and use it to power my center channel (Def Tech CLR 3000). My L&R mains seem to have more depth and dynamics with the 3806 not having to power the center channel.
The bi-amping feature is nice, and I'm happy it's officially included with the 3806 as it was possible with the 3805 if you configured it just right, but without the ability to use the auto-eq and with the occasional humming side effect experienced by some users of the 3805 biamping.... I use the bi-amping feature to power my Definitive Technology BP2000's. I set the 3806 to run the BP2000's set to large and run the sub in each BP2000 off of the L or R preamp outs.
The auto-eq in the 3806 though, is the only real aspect of the receiver I'm disappointed in. I've heard so many people rave about it, but I've been unhappy with it's sound despite MANY recalibrations and different speaker set ups. I currently do not use the auto-eq feature. I may use the manuel eq feature in the future, but right now I'm only using the sub eq's built into each of my front channels.
The remote could be better; it's abilities to control other components are limited as there just aren't many buttons, so for advanced command buttons (like the subtitles or audio buttons on your DVD player remote) you have to keep going to the players remote. My old universal remote is the Marantz RC2000. Even though it's as old as it is, it's a hard act to follow with it's capability to control other compenents so extensively.
With Denon's announcement @ CES of the soon to be released AVR-2807; despite it having 10 less wpc & no Denon-Link, I'd have to say I'd heavily consider going with it before buying a new 3806 right now. It appears to include many of the same features as the AVR-3806 plus the newer HDMI version and the ability to connect to denon's new iPod dock. The 2807 does take a step back with no AL24 Processing (3806 has it on all channels), the 2807's DACs aren't going to be as nice as the 3806's Burr-Browns, and again no Denon-link with the 2807.
I'm not sorry for getting the AVR-3806 when I did; I think it's a higher quality audio product than the 2807 will be, and I needed a new receiver when I bought it! For those who haven't taken the plunge yet thought, the AVR-2807 (at least on paper), looks like it will be a nice choice for the HDMI compatibility concerned & iPod fans.