If you already have a good audio receiver and only watch BDs and DVDs, get the Oppo 93. It will only cost you $500.
However, if you need a new audio receiver, an HDMI switch, and want to watch DVDs, LDs, and possibly other SD sources amazingly upscaled/deinterlaced, go for the Onkyo 809. It is an audio receiver and high-end video processor (with 8 inputs) all rolled up into a nice, price-effective $700 package.
For me, I currently have 2 BD players (1 dedicated to BDs, the other for DVDs) and a high-end laptop attached via HDMI, an LD player connected via composite (since LD video is in composite format), and a DVD recorder attached via component (for testing purposes) to the Onkyo 809.... with 3 inputs to spare for things like game consoles. The 809 also has a phono input if you still have a record player, and 2 HDMI outputs (useful if you have a TV and a projector)
The 809 is sitting in my living room, with a 7.1 Klipsch speaker setup.
If the 809 is out of your price ranged, go for the 609. It has fewer inputs (6 total), lacks S-video support, has no phono input, has only 1 HDMI output, and uses the QDEO rather than the Vida... but the 609 is half the cost of the 809 and provides almost-as-good video processing.
My 609 is in my Sony 5.1 bedroom, with a laptop, BD player and PS3 attached via HDMI. I also have a combo VCR/DVD recorder attached to the 609 via component.
Both have USB inputs (1 on the 609, 2 on the 809) so you can attach your iPod and listen to your songs via the receiver's speakers.
Overall, based on the LDs and DVDs I have watched (subtitled anime, live action titles, some in 4:3, 16:9 and even wider).... I would give the 809 a score of 8.5 and the 609 a score of 8.0. (A score of 10 would equal Blu-Ray quality). For reference, I would give the Samsung BD-UP5000 player an 7.5 and the Oppo 981 upscaling DVD player a 6.0.
Left on my itinerary is test the identical media I have been watching on DVD to my friend's Oppo 83, and another friend's Oppo 93. My friend with the Oppo 93 is also considering buying a Lumagen... so it will be interesting to score and compare all these devices.