I had a chance to do a demo ride this weekend. Was a bit disappointed that we only rode the sleds for about 2 miles each, but here are my impressions.
Viper ltx - great motor, comfortable, sounded a bit "tinny".
Viper xtx- not enough seat time to really tell any difference over the ltx.
Vector with eps and sway bar thing - eps was cool, very easy to turn, even compared to my phazer( but I have lots of ski pressure and 10" carbides). Seat felt like a couch, much cushier than I remember on the vector I rented a couple years ago.
Some things need set up different on vipers I prefer more ski bite, brake felt like it was too low on the bar.
Demo guy pointed out the sway bar thing, but didn't talk much about it.
At the end of the ride, they asked if I was ready to trade up from my phazer to a viper. Nope, I like the narrowness of the phazer. I can pound it and hang off it easy. Would like the power, but really any other sled seems huge to me. (5'10, 180 and little upper body strength)
Demo guys were cool. Could have chatted longer. Thought about mentioning the disappointment that 2015 doesn't' have a phazer replacement, but decided not to.