Some of us use 8 frame equipment to help with the weight  problem.  I'm considering going to 8 frame western (6 5/8) exclusivly.  The weight per box is lower, the center of gravity is closer to me, my back has an easier time.
 
Yes, I need to have a larger number of boxes, the cost of equipment per hive is a bit more and I may have to work and super hives more often.  On the other hand, my 12 frame extractor handles the shorter frames better (gets the honey out of the bottom 2" of the frames better, easier), the hives load on my truck easier (and more of them per load), my back is happier and I may actually be able to have completely interchangable equipment.
 
The trials I have made so far indicate the colony acceptance of such an arrangement is good.
 
 
Dennis
Southern Oregon, USA, Sideliner