Amazing!
This is a fantastic "do all" piece of equipment. The amp and cabinet simulations are fantastic and the effects sound as good as any stand alone pedal. You will have to do a bit of tweaking on the settings for each amp/cabinet/effect to get the exact sound you want, but it's a pretty quick process. I used this with headphones for a while before buying a FRFR speaker. Both sounded great. I'm pretty sure 95% or more of all players could not tell the Helix from whatever amp it was modeling. It's fairly easy to use, although I've only scratched the surface as to what it can do. This is a great piece of gear that I would recommend to anyone.
JM
NC