Nope
Some may argue with this, but I don't think it's a big deal at all that the 4306 isn't THX certified. The Denon receivers have excellent pre-amp sections, which make them excellent processors should you decide to add external amps in the future. Also, the iPod and Ethernet interfaces are nice.
However, the 4306 supports HDMI version 1.1, which most other manufacturers support as well. This version is relatively old and if you plan to connect a cable box to the receiver, do some research into potential problems (most issues are with the cable box, not the receiver).
Hope this helps.