No personal experience about the Mesa, but...
Originally Posted by Bassmec
The 135 is not my favourite fender amp as unlike its 100 brother, it's not very nice on breakup at full power, as it's got a very stiff power supply and an ultra linear output transformer, Just to try to wring the last few clean watts out of four 6L6 output tubes.
I can wholeheartedly concur with that observation.
One of the reasons why I sold mine (135) back in the day, was the fact that it didn't sound very good.
IMO the break-up is actually worse sounding than on some transistor amps
So, out of those two, Mesa would be my choice.