I think its the best amp sim out there. Even above most Line6 hardware stuff. It takes a little tweaking, but it has some AWESOME presets to get you started. Its most useful to me on big rock choruses on the bass, for making poorly recorded parts a little livelier and on vox every once and a while too. I also find it great for scratch guitar tracks for those times when the guitarist shows up for drum tracking and either doesnt have an amp with him or just wants hang out in the control room and do his parts.