I just -- like, just yesterday (squeeeeee!) -- bought a pair of Salomon Optimas and I am so, so, so stoked on them. I was seriously married to Burton. I went from Ride boots to Burton and thought the B's were the be all end all, and yesterday thought it would be more of the same. The sales guy had me try on a Burton Emerald on my right foot and the Solly Optima on my left, then I wore them around the store for an hour while we talked about bindings. By the end of the afternoon I was truly, madly, deeply in love with the Salomons. I couldn't believe the difference in comfort -- after an hour the Burton foot, in fact the whole leg, was tense and tired and I was just standing and walking around. I found that anytime I leaned forward the Solly really hugged my heel without vice-gripping it. I don't know how exactly the F20s stack up against the Optimas, but I'm super-impressed with Salomon and I have a feeling they'd be a great choice for you too.