I've driven every model of Epic and I can say that they all drive and handle very well, and are roomy and comfortable for the particular type of boat inboard boat they are. The 21 ft boat is a blast, it jumps out of the water and corners on a dime. It makes a wake similar to an Epic22/X22 if you sack it out. It is a pretty "big" little boat, 21 ft is big for a closed bow. That is good, btw. The V drives are huge inside, and have a different hull supposedly made for wakeboard wakes.
They're all good boats, it really boils down to how much room you need. The Epic SX has below floor (in hull) ballast tanks, I will be revamping the ballast on one soon;) HEY TERRY! they can be kind of slow because of the .5 in solenoid valves. Hey, you can push a lot of water through a .5 in hole, I'll put a 2000gph pump on it:0