I looked over this list..being an avid guitar player myself (8 years so far)..here's my beefs
I didn't see any Aerosmith on the top 20. Anyone who has looked at the tabs for Dream On know that that has some serious solo's going on...It may not be the fastest...but definitely difficult for how smooth the transitions are for the song. Granite it doesn't add up to Crazy Train or Hotel California...cause those are some insane solo's..but I don't think Bohemian Rhapsody or Heartbreaker can be up there...Heartbreaker wasn't much or solo effort and more power bars
One final thought in this...though everyone just loves Stairway to Heaven, I hardly would rate it being the best solo out there..Its a 7 min song going at like a tempo of 80...Hardly that of any extreme difficulty. Unless ur ranking solo's based on popularity and not on true talent of playing them (I have no problems picking up Stairways tab, glancing over it and playing right along side the song within a few hours)
So my final thoughts...
FADE TO BLACK FROM METALLICA...GREATEST SOLO EVER HANDS DOWN!