If you like Onkyo, I know that someone at AVS got his for $599 at Frys yesterday, and that Amazon recently dropped to $650 two days ago. shoponkyo dropped refurbs to $499 in the last week, but I think they're all out in a day or so.
Every brand has their fans. Onkyo is very arguably the best in value, but they appear to have very poor CS. The nice thing about Amazon is that their CS just might make up for it.
The 805 is better than even the upcoming 806. The Ultra amp will no longer be available in the 80x receivers, but only 875 and up.
The 805 also has Burr brown DACs, where the 806 will "downgrade" to Cirrus just like the 70x series.
However, you might not need this much amp with Klipsch speakers that are known to have high sensitivity. Its very heavy (about twice the 606 or 705 or 663). Its also considerably larger.
So the biggest advantage over the 705 is definitely the amp. 606 does not have preouts.
663 cannot matrix hi-def HT bitstreams for 7.1, but can for m-ch PCM (PS3 users). Only 2 HDMis, and bass mgmt limited to one selectable xover. OTOH, its the cheapest way to go "separates" as it has preouts at an affordable price. 663 also clips BTB/WTW for HTPC users.
The HK and Denon I know nothing about, but I think the HK might have been having a lot of issues lately. Something to look into, Im not sure about that. Denon is a brand that is widely respected.
