I'm sure people would happily discuss this in Shoes & Gear.
I usually ride thunders and tried indy mids when a friend rode the same deck, wheels were about the same size too.
My personal opinions that might not be similar to yours at all:
1. They turn better, which is pretty useless because thunders already turn great.
2. The pop is disgusting if you're used to thunders. Even though the indies are wayyy heavier, the pop felt extremely light to me. Like you can only use half the force and need to pop a lot quicker. Imagine skating your setup, but with 10mm smaller wheels. That's pretty much what it felt like to me due to the decreased pop angle.