My opinion:
I have
a Diezel 2x12, which had Vintage 30s. I play an Einstein. I changed the V-30s against Classic Leads (80), G12 H30 Heritage and G12-65 (old one from 197? and a new Heritage 65). I'm running a 65 Heritage mixed with a G12H30 Heritage now.
The 65 is a bit midrangy in a positive way. It supports lead playing a lot, is smooth and vintage sounding. I wouldn't choose it for metal or harder rock. I like it better than the Classic Lead (which is a bit nasal) and a lot better then the V-30. The 197? 12-65 was a bit smoother than the new heritage 65 (maybe, the new one will be the same after a while of playing).
It is a matter of the style, you are playing. 65 is good for Classic Rock, Blues, Jazz, especially if you are playing lead. For the pure Classic Rock rhythm things I prefer the G12H30, which is a bit more aggressiv and cuts very well through the mix.
The G12H30 Heritage is a bit kind of stiffer than the 65 Heritage - you have to work more, when you play lead with the G12H30 - as I said, the 65 let your lead-notes flowing, makes a good rhythm, but isn't as wild as the G12H30.
Greetings