I've recently bought a Classic and completed my Mod 1
I looked at all the popular units available, and even got to try a couple, but i never considered the Sport Kiss.
For me, there was two reasons
1/ The smaller scrubber
2/ The shallower depth rating
I wanted a unit that i felt i could "grow" into, and would suit the type of diving that eventually i hope to be doing. I felt that, as the Sport is aimed more at the Recreational market, the Classic fitted the bill.
Some good points regarding replacement of damaged parts on a Sports have been mentioned (scrubber head etc), and maintaining both of these units has to be given some thought.
For me, once you decide on a Kiss, be honest with yourself, and choose the unit you'll get the most out of.
Paul.