Howdy,
I tend to spend a lot of time in a non-EVDO area. I typically get between 20-50 emails a day, some of which are tend to be time critical. Before VZW upgraded their 1x network to allow incoming calls during a data transfer, I would have to set Active Sync to check every 15 minutes (or longer) to keep the amount of missed calls to a minimum. I also use Exchange 2003 sp2, so the emails being pushed were constantly connecting and causing me to miss my calls. Luckily, VZW made the upgrade not too long ago, so I'm able to keep the 'push' settings when I'm in the 1x area. In your case though, as it doesn't seem like you get that many emails, I don't see any reason why setting your AS to get sync every 15 or 30 minutes would be a problem. In fact, with these settings you will most likely even see extended battery life, as usually in a 1x area, it takes the device longer to sync up. When you travel to an EVDO area, you could always change it back to 'As Items Arrive'.
Hope this helps...
