Hi michael....dunno will this be much help to u anot....i have htc HD2 and tend to change to DHD when its launched...however i have ported my HD2 to android version and found out that the battery life is significantly better than win mob (totally trash).

TO BE HONEST....I doubt the screen size for DHD will do any better on battery life even with better processor...i own a iphone 4 as well at the moment.

From my usage...my HD2 and Iphone 4 used to surf the net and sms....HD2 will have around 3hours of unplug time from the charger. Iphone 4 (well have to admit steve jobs did a great job) able to clock up to 5hours while surfing the net plus sms....

As for calls...i talked on the HD2 from 7.45am till 8.45am the battery will be drained from 100% to 85% using android platform (it's worst for win mob)
Iphone 4 for one hour of call time will need 10%....so u can do the math for comparison....

Things get ugly when u turn up wireless tethering for HTC....it wont last u till for 2hour if i did not remembered wrongly since u mention u nit connection from 8am to 7pm....but as for me i use to charge it to my work laptop while turning on wireless tethering....

Iphone on the other hand...i dun believe is a fair comparison on the internet tethering as HTC can support more than 1pc at a time for the connection while Iphone only can support 1 device.

well...i strongly believe the huge screen play a big part and i dun think DHD can fulfill your requirement....

i am a HTC fan and thinks Iphone4 is just over rated due to the apps...just my two cents...hope it helps....

This post has been edited by hopeless1: Oct 3 2010, 03:41 AM