"Unfortunately, the player uses the inferior (in our opinion) Genesis chipset, and while Panasonic has done an admirable job of squeezing the last ounce of performance out of it, it still can't match up to the Sage or Silicon Image chipsets."
I always thought the RP-91 used the Faroudja DCDI chip but I was wrong. I may pick up a Mitsubishi DD-8040 this weekend. From what I've read, its a rebadged Denon 1200 w/better zoom features. It uses the same chip as the xp-30, I believe.
Has Mark stated, the 91 does not use a top quality deinterlacer. It's deinterlacer does allow for scaling on non-anamphoric dvd's, which the Faroudja chip in the XP30 does not. Other than that, the 91 and XP30 use the same MPEG decoder and both have nearly equal reference quality basic video output. The XP30 is essentially an RP91 with better deinterlacing due to the faroudja but at the cost of non-anamaphoric scaling.
One thing I've noticed with my RP-91 -- it's deinterlacing performance seems to be improved with the latest (v. 259) of the firmware. The RP-91 has its greatest difficulties with video-based material, but Star Trek Next Generation episodes look much improved since I upgraded from ver. 250 of the firmware.
If you have Nero, you can download this zip file that has a Nero image file.
Once you burn the Nero image to a CD/CDRW, just pop the disc in the RP-91 and it should detect it as being a firmware update disc, and you'll be asked to confirm the update, and then it'll take 3-5 minutes for it to do its thing.
Patrick, your firmware update link seems to be inactive or no longer working. If someone needs this zip file and can't find it elsewhere feel free to e-mail me and I can arrange to send it to you over AIM or MSN Messenger.