Interesting scenario. I looked at both of those phones before getting the Hero. Around here we don't have that many carriers or providers so some colleages and I compare our smartphone choices and discuss over coffee from time to time. When we put all three at the same table and ran through some common tasks such as browsing to web pages over 3g, speed of app download, battery life, etc - the Hero won hands down. While I agree that the iPhone looks like a nicer piece of kit and has more appeal from a raw hardware factor, I utterly hated its lack of flexibility. Everyone is at the mercy of Apple which is ok for the masses but frustrating for an application developer. Also, the cost is INSANE.
As for the HD2, first of all it doesn't have north american 3G frequencies so it got slaughtered on speed tests right away. Next, its a WinMo device which means that it struggles under the weight of its own OS. Again, I like the way the hardware looks but there was too much to sacrifice for that.
As for the Hero's looks, I stayed away from the G1 based on its hardware design. I found it too bulky, I'm not a fan of the physical keyboard, and I found it too bulky overall. With the hero, I can tolerate the chin and the new form factor really appeals to me while capturing the flexibility of android and the community spirit of an open OS. I certainly don't regret my choice!