I had (HAD) a marshall AVT150 head. Granted, it was a good head. The distortion was good and the clean was ok. The acoustic sim sounded like crap and went out on me after about 6 months. The effects freaked on me too. When I turned it on the effects would be freakin and loud and wierd so i would have to shut it off and then it would be ok. There are so many amps out there and for around that price, the crate shockwave, or tidalwave blows that amp out of the water. Huge sound, 3 seperate channels, built in tuner and effects. Plus it more than doubles the marshalls wattage. The crates have 350 watts!! Huge/better sound and huge watts for the same price as marshall, im sold.