I agree with Ben. I love living in a manse. I didn't have to come to a strange city, try to figure out which neighborhoods were best, find an honest Realtor, deal with mortgage companies, etc. We moved in to a beautifully remodeled home that our tiny congregation had also stocked with basic provisions. When we eventually move on, we will not have to deal with selling this house (much less possibly facing two mortgages). Repairs and maintenance are handled at no expense to us (though Ben must have it easier---Tim has to deal with all the repairmen for both the church and the manse!). Having the manse near the church (we can see the property from our adjoining backyard) is convenient, too.
Now, given that's not an option at most churches, I'd recommend renting unless you feel fairly certain you'll be there, in that specific house, for five years or more. In a new city (which is usually the case), that's a big commitment to make given the limited time one has to explore before the move.