Rogue Audio M-120 vs M-150

Hello;

I've had a pair of Rogue Audio Magnum M-120 amps for about 18 months now and drive them with a Rogue Audio Magnum 99 preamp. I've been extremely pleased with them, to say the least. Well I recently called Mark of Rogue Audio to order a new set of output tubes and he made me a great offer on upgrading my amps to the newer M-150's. Unfortunately there is no place near me where I can listen to the M-150's so if I upgrade it will have to be without hearing them first. Mark thinks I would be happy with the upgrade and he hasn't steered me wrong yet, but I was hoping to get some additional input before making a decision.

Mark tells me that the newer design produces far less heat, has about double the output tube life, and is more dynamic and transparent. Given how pleased I've been with my current amps I'm more than a little hesitant, but if I can take my system up a notch at a reasonable price, why not? Any input will be greatly appreciated.

Have a good day
Brad