Viggen - do it - you will be a happy guy- I could not be happier with mine.
First, Integra is a flagship line for Onkyo - sort of their Lexus.
At $1,300 he is just a few bux above what used ones have been going for here. Make sure it has the latest software. You might be able to push him some.
If you read the boards diligently you will find that there was some rough sledding at first release but everything has been all mo betta for some time. You will also find some comments about them running hot which I have seen no sign of at all.
There are a lot of things to really like here - the Audyssey EQ is a marvel and works very well (we ran an analyzer on it). I am running my two mains in the bi-amp mode since I only have a 5.1 system. The HDMI switching is rock solid. There is a nice set of HDMI specific features like lipsync which are essential. And it sounds very good on music and even better on movies and TV.
I just buzzed through the e-brochure for the 9.9 and it seems that the differences are all software or firmware - the hardware seems to be the same.
The 9.9 has a couple of more nice to have but not deal killer Audyssey features. I did not take the time to download and check out the owners manual to see what they actually mean by "ISF Certified Calibration Controls per Input (Custom/Day/Night)". BTW compared to other manuals from Denon and B&K the Integra manual and programming is the model of clarity.
One shortcoming if you want to call it that, of the 9.8 is the Reon processor settings are applied globally - so your 1080p BluRay, your 1080 DTV and your old DVD player are all managed the same. (Hopefully this is what the new ISF function mentioned above addresses) When we did the ISF set up we completely bypassed the Reon. We uprez the DVD in the Oppo. The BluRay, Apple TV and DTV go straight thru and the Pioneer does whatever is needed at the end.
Which brings me to Kr4s thoughtful link to the Stereophile review. And the subject of the miracle of HDMI. As Forest Gump liked to say, the Integra and HDMI go together like peas and carrots... Sure it will work fine without HDMI or HD but you won't get all the magic in the box.
This is especially true when you consider that you can have the soon to be announced Oppo BluRay/DVD (or a Pannie BD30 and a Oppo 983) and a new DTVHD box for under a grand. The BluRay (1.2 and 2 standards) is an essential component because it is the only 1080p source and it is the only way to get the uncompressed Dolby and DTS formats now being offered on some of the latest movies. A big wow.
The remote is massive and reasonably hateful requiring reading glasses but very easy to use for programming. I have all my devices integrated through a Logitech Harmony One which once programmed makes it very manageable day to day.
Finally, I am not aware of anything near this price point that delivers this feature set. I do believe the urban legend about it being a handbuilt statement piece. Plus I think the next stop would be the Marantz separates. And again without HDMI sources and BluRay it is a moot point anyhow.
I do very much like having a separate amp. Gives you a huge amount to choose from especially if you are only running 5.1 - everything from Krell and Pass to Anthem and Butler.
Finally if you are undecided a lot of folks are buying lesser receivers with the same or similar feature set then using the preamp out to go to the amp of choice - something you could of course do in stages.
Ping me if I can be of further help. I do have a few more posts about all this you can find as well.
But at $1,300 its a no brainer if you plan to bring your entire system to a new level of performance by using all the related technology (HDS, HDMI, BluRay)