It's a good amp...I love having three channels to toy with. My biggest beef is the volume on the clean side is far less than what's available on the crunch and lead channels, but mine has been modded a little so that may have a play there.
Drew's right on the tubes....but at a minimum have it rebiased, factory biasing tends to run on the cold side and these heads seem to be pretty sensitive to tube selection and bias settings (at least mine is).
It is an amp that has to be played loud to be really appreciated for what it is. This is not a bedroom machine by any definition. In stock form they tend to be a little buzzy sounding until you really get the power tubes into play so using the VPR function or an attenuator will help.