I had a Sakura (Tissue-Tek) coverslipper in a previous job...about 9 years 
ago.  One of the things we noticed was a tendency for the tape to become 
"scratched" as the slides were being filed/pulled for review/filed/pulled, 
etc.  It wasn't really a huge problem, just something that bothered one of 
the pathologists who liked to take photographs.  It didn't interfere with 
reading the slides, it just seemed to annoy him.  Other than that, we had no 
complaints.

Diane Mahovlic
The Cleveland Clinic Foundation

PS- FYI, I have heard that that is one of the reasons we don't have a tape 
coverslipper here at CCF, but I don't know if that is the "official" reason.