Up to this point I have built my own equipment, so changes in any direction are not too big of a deal cost-wise.
Although, I have considered (and to some extent still am) long langstroth, I am pretty settled on the langstroth frame itself.
I assume many of the benefits of horizontal-ness could still be accomplished with just the difference from 8-10 or possibly even 12, not the least of which might be the use of frame feeders. As well, being able to use a follower to "right size" things horizontally. Or have relative size configurations to be able to do resource hiving by doing things like 2 of some size super over top of 3 of another, or even 1 over 2 for multi-queen configurations.
Other than the lifting considerations which seem to be the same arguments for going from deeps down to mediums, and for 10's down to 8's are there any other good reasons to not use 10 frame deep equipment?