Sadly I only ski 12 - 15 days a year, and don't claim to know all the technical stuff mentioned by Philbug. I was looking for something very different from my old Volkl P40 energY F1s. I wanted a ski that handles as many eastern conditions as possible. Yesterday I set myself up at Sugarloaf to demo as many options as possible. Also wanted something completely contrary to my GS skis. Going in I was hoping to demo Soul 7s even though I've been told I wouldn't like them because I come in at 240 lbs. I also wanted to try the Volkl 84 RTMs. In the end my first pair out where the Nrgy 100 185cm. I was a little nervous never being on anything wider than my GS skis, but half way down the first run on rather hard slightly corny conditions I found myself leaning on these skis as hard as I could and loving every moment. Other than the sound I could barely tell the difference between scratch in the middle and the built up stuff on the sides. Over the course of the next four runs I kept looking for more and more crud to go through and not having any trouble with any of it. Runs 6-8 were on (short for me at 6'2") Volkl 84 xtm 171s, they didn't have anything longer. After three runs, I felt little difference then from my regular GS skis. Nice edges though. The next two runs where on Blizzard Bonafides 187s which I found very tiring. Keep in mind I was shooting these runs as hard as I could putting in as many turns as I could. Yes I was tired hungry and a little dehydrated, but I wanted to revisit and see how the Nrgy 100s felt after all of this. I was able to easily manage five more runs on the Nrgys, the last two somewhat toe curling, but a lot of fun. After 14 hard nonstop runs and numerous climbs back up the hill from the ski shop at Sugarloaf (those of you who know) I found myself at The Bag reading this review and comments of which became the final straw. Comments like "friendly ride" were so true. I bought the barely used demos Nrgy 100s only wishing I had at least tried the 90s that I hadn't known were available, alas I had already changed and put everything in the car a quarter mile away. In the end I was thinking that the extra 10 might help on the occasional powder we get here in the East. If I can replace my 15 year old Volkl GSs, I feel I'll have all that I need for two very different but easy choices for a days skiing in the East, ripping the groomers on one, crud and everything else on the other. This is not to say the 100s weren't a lot of fun on the groomers. At a guess, because I haven't skied them --- someone in the 180 lb or less might find the 90s slightly more versatile than the 100s. Again, that's just a guess.