wireless sync is bascially the active sync with out the USB cable. you can receive email and in put contacts to your computer and they will sync right over without having to plug in your Q. the email portion pushes the email to your Q as soon as your Q sees that you have mail. where as if you set up a pop3 account it will only grab the email every 15 minutes regardless of when it was sent. the wireless sync doesnt drain the batter that much, i wouldnt worry about that. you also dont have to worry about transfering data all the time if you have the unlimited data plan from verizon (or alteast up until 5gig usage but i wouldnt worry about that). if you dont have that or any plan at all then you need to worry about it since it will cost you a small fortune especially if you have stuff set up to get your email or receive weather updates or using an instant messanger.
i hope that made some sort of sense for you
