i have been processing film in trays for about 10 years, and even though i have a unicolor drum &C i can't get myself to acutally use it for sheet film. trays are easy to deal with 'cept when you can't remember which one is the dev and which one is the fix ... the only problem with tanks ( daylight ) and trays is that it is hard to use a replenishing developer like dk50 or harvey's 777 --- you always have to pour it back into the big-jug which is messy and a pain ... i guess everything has its trade offs