The HTC Hero is the current Android phone of choice, due out in a couple of weeks hopefully. Orange, apparantely, are doing it free probably from £40 tariffs, estimate £100 at the £25 tariff… no confirmation of that yet though.
All smartphone battery life is the same, I have the XDA Orbit (HTC P3300) and I get the same as reported by flipiddy, GPS, WiFi, Bluetooth all consume power but you can turn those on as you need them. In the car GPS & Bluetooth are on, but a car charger sorts that… an essential.
There are plenty of video reviews of the Magic which can give some indication of the fluidity of the controls and responsiveness. Android itself is a brilliant platform and fully customizable (unlike the iPhone) and the HTC Sense of the Hero is just wicked. Most of the Apps for the Android are free, again unlike the iPhone.
I'm holding out for a Hero… 😉 …(sim free)