I don't work for the company so don't sue me...
I took delivery of the Oppo a couple weeks ago. I've watched about 5 movies on it so far, and like Gonk said, the quality of transfer on the DVD will determine how close to HD it looks. For example, my Gladiator DVD looks spectacular. I've watched a few rental new releases (I was gone for 4 months so I have a lot of catchup to do when it comes to movies). One of them (can't remember title, it was so forgettable) didn't look quite as good, or "HD'ish".
As far as audio, I'm only capable of playing CD's or DVD-V on it, as my pre-pro is still circa 1995. When I get my 990 I'll have to buy a DVD-A or two and try that out.
I don't think it plays SACD...at least it doesn't list it. Maybe Gonk knows...
As far as the company's customer service, I called them for help in flashing the firmware and they were very helpfull. No complaints there.
I haven't tried too many other DVD players, but this one definately makes a DVD look very good on my HD RPTV via the DVI connector. It only upscales via its DVI output however. If you don't have a DVI or HDMI input on your TV, then you wouldn't want this unit.
In my opinion, if you want an upscaling DVD player for your HD TV and you have a DVI or HDMI port (you could use a converter connector) you can't go wrong with the Oppo DVD player, especially for that price. I bought mine from the company's website, and no problems with the transaction. Very quick shipment.