I'd like to have one for a front mount sweeper to clean up jobsite pavement, but the cost of the sweeper and removing the FEL to mount it seem prohibitive.
Probably easier to just buy another tractor with a dedicated mid-PTO and front implement, like blower or sweeper already mounted!
As far as mowers go, I'd love to have a sickle mower and the side mount units are really cool, but not easily removed/installed. Same with the MMM. My Challenger will take an 84" MMM, but they really reduce the GC on the tractor for dirt work.