I did purchase a oppo bd-93 instead of the Marantz UD5005. I ran some bluray and 720p dvds through both PS3 & the oppo. If there was a difference on bluray discs, I might not have noticed it. Load times felt much snappier on the oppo.
Where the oppo clearly outshined the PS3 was in 720p playback. The oppo breathed new life into many dvds which I had previously accepted as "this is as good as it gets". The upscaling coupled with a plethora of zoom options meant that I could get a much sharper picture which filled the entire screen.
At $499, the oppo isn't an impulse buy - but if you watch upscaled content and desire the best picture quality, it's clearly the better option.