i think Tubes are better for Jazz and Classical music like Vaughn Williams string works where you can recreate that ethereal sound you get with a live symphony. for Rock its solid state all the way, so ideally 2 amps are needed.
This might come as a shock for some but its impossible to design amps or preamps to favor a certain genre of music. If the amp is bad on massed strings it will be bad on electric guitars with heavy drums too.