Obviously, the only true way to tell how they sound is to demo them. in your system. If this can't be done, at least compare what each amp has to offer. The Evo series offers balanced inputs and a remote that lets you switch between triode and ultra- linear operation. The Evo can also serve as a mono block should you decide to upgrade to more power. It also offers auto biasing and "bad tube" indicator circuitry. These are all features that may or may not be important to you but at least are worth considering. Both amps are well built with quality components and neither is likely to disappoint, but again, the real test is how they sound in your system.
J.Chip
J.Chip