I used one with my Mark V 25. For me, it was absolutely critical to get the low end that I wanted out of the Mesa. It adds a lot of power amp control that the Mesa lacks. It also adds depth and thump to the low end, and can add some high end presence that is different from what the Mesa was capable of producing on its own. It also worked REALLY well for getting the volume lower than I could get it with just the Mesa on its own. Add to that the fact that you can match any amp ohmage with any cab ohmage through the Power Station, plus its self attenuation capabilities, and the ability to run pedals direct into it, or preamps into, and yeah man. Seriously, one of the best pieces of gear I have owned, and I will buy another one eventually.