I bought this as the HD1 version became obsolete with my new phone. The iRig is a perfect tool for home practicing with your phone or ipad. I've even done some recording with it for demo purposes with good success. I think the sound on the HD-1 was a bit better, but have no real side by side comparison and it might even have to do with the phone jack providing the sound on this one. It's not maybe the most rugged thing in the world and some of the cables are short, but at least you get all you need in the box. No complaints what so ever.
The Amplibtube software for ios is not on par with e.g. JamUp Pro but you get by. The software version is yet another beast, but I still think that I get better sounds from e.g. LePou. You can off course buy a lot of extras for both platforms, but haven't taken that route yet.
All in all a good companion and for the price I think quite unbeatable especially with the bundled software.