I'll have to call [citation needed] on "double battery life". I have 3 jabber accounts with keepalives, skype with it's own keepalives, sip with reregistration and pinging, additional status messages are transmitted every couple of seconds on all of them. If I turn all of them off, my battery life does not increase 2 times. ~5-10% the last time I checked. I really doubt disabling the dhcp-equivalent on 3G can improve the battery life 2 times.