Small Blocks are great if you ask me, I’ve got two loaded in an oversized pine 2x12. I use that cab with a 6505+ doing 80’s 90’s VH/Demartini/wetdry rock sounds. My biggest gripe with G12M’s is that they can be too brash, bright and even harsh in some rigs, Small Blocks don’t do that but the “bark” is still there. It’s like an idealized greenback, in most scenarios it’s the greenback sound I want to hear. Another example like this would be Aldrich/Hot 7 vs a JB.
All that being said, I’m sticking with the G12H Anniversaries for my Quick Rod until further notice. They’re great together.