How much better are they than the first generation? Apple says the noise cancellation is significantly better but I have my doubts. Do they sound much better than the original Pros? Better bass?
Much better and faster. In fact, you can put them in the case for 10-15 minutes and go from almost zero to 50% or more. With the AirPods removed (charging the case), wired charging:
APP: From 50% after 10 minutes, it was up to 61%.
APP2: From 58% after 10 minutes, it was up to 68%.
For a full overview of both generations, you can check the headphones page on Apple’s official site.