I have first used Jobo tanks (I forgot the ref. number but there were not the
expert drums. I encountered problems: developper action was not even on all
the surfacer of the film. The same result has been noticed by testers in View
Camera Magazine. So, I swithed to Expert Drums as recommended and ... all the
problems of uneveness desappeared. Except for their high price the Expert
Drums are wonderful. I strongly recommend to buy the pump, so you could easily
open those drums without using a hammer like I did first...
_michel