I got the line6 riff tracker recently for fun. Despite its many amp models, I only manage to get 1 or 2 I like. I sounded a little harsh or artificial compared to real tube amps.
I happen to love the marshall valve amp that I have, but wanted a something for practise at night, after using Korg Pandora for years.
On the plus side, it work as a good practise tool using pc or laptop. The recording software is easy and fun enough to be used. Comes with metronome, drum rythym, tuner, access to internet to download tone setup of various artist etc. Not the real thing but quite a good toy.