For the price it is an easy decision. Certainly you could determine the differences on your own and decide which you prefer. Having owned both models, I will tell you the Heresy's will be a bit more forward or 'brighter' than the 10's. Some prefer that, some don't. The tube amps you are using should ameliorate some of that brightness though. My advice, get them and then enjoy a nice glass of wine while listening to some Mozart. Enjoy!
klipsch heresy
I have the opportunity to buy a pair of 1982-83 Klipsch Heresy at a good price. I am currently running Klipsch KLF-10s as my mains with a Velodyne sub. I have a 2A3 Set power amp and a George Wright AU-1000 preamp. Just wondering what differences in sound I can expect from these two speakers, and what if any differences are there in the sensitivity of these two(decibel levels?)