Alan,
I've been using the same neg / slide scanner at work for about 12 years and never had a problem with it......ermmm - until about 3 weeks ago when it died completely. Can't speak about any others as I've no experience with them, but the one I'd been using was the Nikon Coolscan II.....not cheap - but after 12 years of constant use and never had a problem with it until I guess I just worked it to death - VERY reliable.
Unfortunately, Nikon don't do the Coolscan II anymore. Their current equivelent is the Super Coolscan 5000 ED Film Scanner, which has a price tag of around £800. Again, not cheap - but if you're gonna get 12 or so years out of it, producing really high quality scans, then it may be worth thinking about.
Just as an aside to this, but on the same subject.......
The scanner I had was bought about 12 years ago and has never had a problem or let me down. When I asked at work if I could order a new one (the one I've mentioned above), I was told "no - we haven't got the money in the budget for it".....I was also told that I'd have to make a VERY good case for it to even be considered for inclusion in NEXT years budget. Reason being "it's not a priority item" - well maybe not to them...lol.... but it is to me. Over the years, I've amassed a huge library of photos documenting changes around South Tyneside......looks like I may as well just dump them in the bin as, if they won't fork out the (relatively) inconsequential amount of £800, they'll never see the light of day again.
Anyway......lol.....got a bit off topic there, sorry Alan.
Tha Canon CanonScan 8800f seems to have a good spec, but it's so inexpensive compared to the Nikon, I'm not sure what the quality of the images will be like...as I say, I can't really speak for any other slide / neg scanner, not having used them - but I'd definitely recommend the Super Coolscan 5000 ED Film Scanner..........or the old Coolscan II, if you can get a 2nd hand one.
Calumet is where I get most of my own gear (as well as work gear) from. Here's a link to their site and the section on neg / slide scanners:
Digital: Cameras & Workflow / Scanners / Scanners / Film Scanners / - CALUMET