I drum scan type 55 all the time.
Ive scanned hundreds of them on my Howtek 7500. The neg quality is superb. I cant think of a better film to use.
If they are processed and washed correctly, they are pretty robust but they are thin so watch out for an errant breeze.
When i process them myself, i leave them in the sulfite bath until the paper starts coming off by itself. I also agitate it every now and them to keep things moving. Then its off too a film washer for 10 or 20 minutes.
The negs come out great and i have to work hard to scratch them. I use 1lb of sulfite to 2L of water. Maybe alittle more due to evaporation.
Anywhoo, type 55 will give you some beautiful scans!!
-ian