I have both the DMP-55 and the BDP-83. While the specs are similar, I find the performance of the OPPO to be superior in the following areas: speed of operation, standard DVD upscaling and playback, and CD audio (besides the added benefit of DVD-A and SACD performance). My perception also is that the Blu-ray audio is slightly better on the OPPO, but I will admit that could all be in my head.

On Gonk's point, from what I can tell, the Uniphier chip in the BD-55 is improved over the BD-30, and we certainly were happy with it, but it still is not up to the OPPO's quailty.

If you are going to use the Panny primarily for Blu-ray with limited SD playing, my sense is you probably would be okay with the Panny. But if you are going to use it even 30-40 percent of the time with SD-DVD, I'd go with the OPPO. We ultimately kept both machines (having gotten a great deal originally on the Panny -- paid $240 new), but if I were buying one machine today, I would buy the OPPO, even if I could get the Panny at the price we originally paid.