Malcolm, The two PVR's that you're looking at are both fine machines, but for the money I would be looking at the Panasonic DMR-E85HS. For starters the panasonic has a 120 GB hard drive. The panasonic also like the toshiba can record in DVD-RAM format as well as -R and RW. I have been using a panasonic machine for some time and I can say its editing capibilities are far superior to any other machines I have seen to date. When you are editing out commercials, cutting and splicing segments, and doing custom title work....the panasonic has them all beat hands down. The 85HS is available for $529.00 at Abes of Maine, which is a highly reputable internet store.
http://www.abesofmaine.com/viewproduct.asp?id=psdmre85hs
The panasonic is only a little more expensive than the Sharp, but offers world class editing, and 40 more gigs of drive space. I would have to say thats all well worth the extra $22.00.
Anyway....I hope this helps.
Mark