In terms of blu-ray, PQ will pretty much be the same. Audio is a different story, at least when it comes to analog. For sound via digital, it won't matter.
Based on testing, the Oppo (or rather the ABT chipset) is definitely one of the two at the top of the food chain as far as upscaling SD DVD goes, but it is still dependent on the disc as well. Good discs look good, bad discs still look bad. My Panny upscales pretty well too, as does my PS3. Can I tell the difference? Yes, but it isn't such a big difference that I would be thinking "I can't watch this" compared to the Oppo. With the Oppo, I am often surprised at how good the upscaling is when watching certain movies, Kill Bill for example, looks almost as good as the Blu-ray. So it kind of depends on just *how* good you are looking for. I am going to hook up the BD-65 this weekend and compare it to the BD-60.
I think we discussed this in a previous thread. The benefits of the Oppo over other players would be the good analog audio section and the top notch upscaling, but upscaling isn't going to be perfect no matter what device you are using.