I don't think that the lip sync is an issue. Here is a fix:
http://www.avsforum.com/avs-vb/showthread.php?t=935808

If you have your tv, receiver and blu-ray player being hdmi 1.3 then you can set the receiver to lip sync to fix it. Otherwise you may have to tweak it a little bit like suggested on avsform thread.

I think this is the better buy than the Denon. The onkyo is around 50 lbs while the Denon is only around 40 lbs. Weight is a good thing with amplifiers. If the O.P. has m80's and the Onkyo is having trouble driving them then he could get a couple of Outlaw monoblocks and the total price is still only around $1200. The best price on the Denon was around $1100. At audioholics they gave this the product of the year and started carrying this and other Onkyo's in their store. The review at audioholics especially how good the audyssey works convinced me to buy this receiver.
Link: http://www.audioholics.com/reviews/receivers/onkyo-tx-sr805/tx-sr805-listening-tests

I ordered mine from amazon this past Tuesday for $680 including shipping and tax. I'll post any problems that I have if I have any when I get it next week. I originally wanted the onkyo 605 so that I could get all the new audio formats from my ps3. Then I read about how good the audyssey was in the onkyo 705 for another ~$100. Then I saw how the weight of the receiver from the onkyo 705 to the 805 jumped from 30 lbs to 50 lbs. I figured that for another ~$100 it will give the dynamics some extra headroom. At $680 out the door there isn't any competion close to the onkyo 805.

- Nick