I'm trying to decide on a new (to me anyways) receiver.

I've narrowed it down to these two:

About the only big deal I see bwtween them in their feature set is the 805 has better video flexibility & the HDMI 1.3 thingy. THEIR POWER RATING IS ABOUT EQUAL AND ALL i WOULD NEED.

The HDMI 1.3 does seem attractive for multi ch. high res audio playback via a single wire bundle, BUT not having heard anything through one, I'm skeptical on it's performance level and would think the Marantz the more musical of the pair... albeit the need for RCA cables for SACD.

The onkyo is also cheaper.

Any other thoughts or experiences here on support or performance, would be super and greatly appreciated.
Actually, selling/buying AV receivers is a lot like it is with cars - each model has it's own qualities, features, and options. You chose according to your needs, likes, and wants.
I would qualify you as to your speakers you have chosen - and you should chose speakers before the power source, yes! If you do it the other way around, it's really backwards.
So, since I don't know your speakers, room, lifestyle, acoustics, listening habits, etc, it's hard to recommend the best choice for you.
Also, how are you connecting your source(s) to your receiver? Do you need direct analog inputs? Or are you only needing digital connection for your sources? This all matters, and some choices will be better than others, depending.
In many cases, I would often chose a lesser priced receiver, and then use the extra money I saved to add an EXPONENTIALLY BETTER MULTI-CHANNEL AMPLIFIER TO THE MIX!!! - as long at the receiver level offered the features I wanted. And now, you can get HDMI 1.3, Dolby HD/DTS Master, video upscaling,
If it were me (and I don't totally know your connection/ source needs), I KNOW FOR A FACT, that you'd get much better overall sound from your digital sources (likely DVD, HD-DVD, Satalite box, music server/Ipod, etc), if you bought a more modestly price receiver, at $1k or under, and then used the other money left over to invest in a better outboard amp!! The amps in ANY RECEIVER are usually compromised pretty well in terms of quality and current delivery!
Basically, sound quality differential between (all things equal and considered) a $3k receiver by itself, and a $1k receiver (or less, often) with a good 3, 5, or 7 channel amplifier connected to the system (instead of using the amps in the receiver) is HUGE!!!!! Basically, the dynamic potential, and overall sonic refinement of a better outboard amp in the system, FAR OVERCOMES any fancy features benefits a larger receiver has! So consider.
I personally WOULD NOT buy a $2k receiver, EVER!!! If I had to use a receiver in my system (and I would rather use a pre/pro if possible), I would use a lower price point, but otherwise good sounding unit (considering digital connections, likely), add an amp, and be WAY AHEAD OF THE GAME!
You see, in the end, it's ALL ABOUT SOUND quality and picture quality for your AV experience! (at least in terms of gear as a factor). Anything else is down on the totem pole, IMO.
That all said, I would say a receiver is good enough in mid-fi applications, by themselves, when you drive very efficient speakers (like horns), or speakers with active woofers, at the least). There are few exceptions, depending on variables, IMO. Still, receivers are on the weak side in terms of power delivery, dynamics, overall sound quality, refinement, etc. So consider your variables. If you rock, play loud, run speakers as "full range", etc, you'll need more power. And even if you run small monitors as "small/80hz", you'll find that dynamics are far superior from a dedicated amp.
If however you deem a receiver is all you want or need, I would keep speaker choices limited, run them as "small", regardless, and look to connect things digitally! If you need direct analog inputs for pure sources, you will find you have no EQ in the circuit, which is very helpful for making the system/room balance!
To answer your question, I would lean toward the more expensive Marantz's over any Onkyo personally. Don't care for Onkyo's sound, myself.
If you avoid amps that employ negative feedback, your remaining choices will be quite scant, and none will be mainstream.
I would not buy a receiver that does not have HDMI 1.3. The 1.3 has both video and audio advantages.

The serious AV/HT geeks hang out on the AVSforum site. Go there and search the archives. You will likely find lots of information about both of these receviers as they were both very popular high-end models.

As I recall, the AVSforum group is pretty keen on the Onkyos. I think there are also many proponents of that Marantz unit on the site. I don't think you could go wrong with either.

I don't personally have any experience with the Marantz line, so take my comments with that in mind. I have owned HT receivers from Sony, Sony ES, Pioneer, Pioneer Elite, Denon and B&K. My current Onkyo SR-TX703 is by far the easiest to setup and use. It also sounds as good as any of the other HT receivers I've used in my modest HT system (I'm primarily a 2-channel guy too). If I were suggesting an HT receiver for a casual HT enthusiest, I would feel very comfortable suggesting the Onkyos.

The only suggestion I would make is to consider your entire HT setup before deciding on a receiver. Many of the current receivers (I don't know about the one generation old models you are considering) provide video upconversion which will allow you to connect a single HDMI cable from the receiver to TV. The receiver will upconvert any video signal (Composite, Component, S-Video, HDMI), convert it to digital and output it over the single HDMI cable to the TV. This could be a great feature that simplifies your ease of use and cuts down on cable cost.

Good luck in your search and ENJOY!

I hang at AVS a lot and the word on the 805 is,it runs hot and has some noise issues. This is early on,whereas the discs and some players aren't standard I'm sticking with my older Marantz and use the analog outs on the player and straight to the display for the video. There are so many inconsistencies within the formats;some in the audio some in the video.--this refers to some players don't output all the audio formats over hdmi and my 1080p projector doesn't do frame for frame conversion. SO,I say do all the homework and make sure your player and display do all the new format is capable of before you leap into your new reciever.