The Amplug is excellent for practicing. It's small, light and easily portable with good sound quality and reasonable volume levels. The ease of use makes this a valuable bit of kit and well worth the investment.
Unfortunately the construction feels and looks quite cheap and fragile, the gain has to be turned up quite high to allow the volume control to remain low to avoid unwanted hiss. Also the jack struggles to reach comfortably down the Strat style lead burrow and has to rest on the bridge on my Ibanez, which is a bit annoying.
All that said, I still would recommend the Amplug Ac30 as these are niggles rather than significant problems. I advise listening to the examples of the AC30, Classic and Metal Amplugs on the Vox website to choose the correct sound for you.