Everything he said, and I second the sometimes significant variance among examples of the same model. I have a TMDR, and I get to hear its tube cousin weekly. It's not exactly the same, but it's really good in its own right, the attenuator/master volume makes it really flexible, and it's *light*! One thing some others convinced me to try is an Xotic EP Booster as an always-on, zero-gain sweetener. The difference is subtle, but significant, and just adds an extra sparkle and fullness without really altering the overall sound. I've seen folks have also done this with tube DRs.