I moved for better battery life. I can get over two days out of my Blackberry Bold which is useful for some of the rides I've got planned, not least LEL next year.
Ironically, I think that it's the apps and general usefullness of the Android OS which kills the battery life. If I turn off non-essential apps, BT and wifi (thus making it as useful as a BlackBerry) then my HTC Desire will easily last 4 or 5 days.
My most used apps are Advanced Task Killer (to remove anything running in the background) and Power Control (to turn on/off wireless connections and automatic updates). And the Battery Meter is telling me that, on normal use and having made several calls and spent time online last night, it's been unplugged since Monday evening (37 hours) and I've still got 47% battery left.
With HTC's own replacement batteries are under £20, there's no way that I'd move to a BlackBerry for personal use - to the extent that I've just (yesterday afternoon) received some money from Mazuma from a BB Bold which was gathering dust.
I've had nothing other than BlackBerry devices for work for nearly 10 years, and with a decent BES connection, they make peerless business offerings. They are, for me, not good for personal use.
Sorry, each to their own and all that but I think, Martin, that you'll soon regret the decision to go BlackBerry.