An ex-iPhone user who has a Hero converted me to Android.
The Hero's touch screen is far superior, IMO. Its sensitivity is very well tuned to human touch. The Hero touch screen is hardware-wise almost identical to the Eris. The Moment performs similar to the Droid, depending on the types of tests.
I played with both in the store, and much more extensively with rooted versions of each phone.
MY bias toward the Hero is related to two more important things. I think HTC Sense is excellent. It slows down the phone for sure, but the way it looks, feels, its capabilities, and its integration (between widgets, apps, home screens, etc) is excellent. It's very connected.
My second gripe is that I can't use a physical keyboard. As a Verizon person, it's why I felt like the Droid was a waste of space. Physical keyboards, I can't bring myself to use. I feel like a teenage girl texting on one. I can t9 faster than anyone I know can full keyboard anyway, and the Hero's touch screen does that VERY well for a touch screen phone. I'm glad I bought the Verizon counterpart.