FRF85B is the official update

Will it do the OTA if I'm using wifi or should I shut that off to have it grabbed through 3g? Is there any difference? I have wifi set to never sleep. I heard it uses less battery that way.. It's only day 23 of testing this but it seems true.
 
If I run the manual official update, will it wipe my phone or just do an upgrade. Running AT&T Nexus One. Currently on Build # EPE54B.