Anyone use one of these or have any experience with them in general? I have been in the process of researching to upgrade my amplifier to something giggable, I was thinking I could just go to a Marshall MG50DFX or possibly a Line 6 Spider II 112 And I came across the Marshall MG100HDFX head for only $50 more than the 50 watt combo, Just wondering if its a worthwhile amp head, something to last me for a year or 2 while I go on a hunt for a nice Tube amp.