The Pro comes with a few extras the regular doesn't like cleaning solution. It it also easier to work into the joints than the regular. The pot life is about the same. They say 80 minutes but after about 30 it starts to stiffen enough that it's hard to work with. If you have 2x2 mosaic on the floor you'll need more than a mini unit as well.
I use the 'PRO' on a regular basis----I can't tell the difference. Just the price. Read the directions--
wait till the stuff has a chance to set up a bit before wiping--read the directions---(I know,Real men don't read the directions!)
Have plenty of sponges--save a nice clean one for the final wipe down.