I'm not exclusively anti-gap. I grew up Catholic, it's pretty common to have an hour between the ceremony and reception; life goes on. We had a nominal hour gap (by the time we had the 'exit' and you include drive time it was really only about 30 min) - I felt a little guilty about it, but we clearly indicated everything with a reception insert in the invitations; it was what it was.
Saturday H and I attended a 1pm wedding. The invitation indicated a "reception to follow" with no additional information. We dressed for an afternoon wedding, drove an hour and a half to get there and figured we'd be home by 6 or 7. When we got to the ceremony and got our programs H noticed on the back that it said "Please join us for a reception at 6:00pm"
seriously?? WTH are we supposed to do for FOUR hours? and with NO advanced notice?
So brides - if you're having a gap, TELL YOUR GUESTS! If the reception doesn't actually immediately follow the ceremony include a reception card in your invitations so that your guests at least know what to expect. We probably would have still gone to both pieces, but at least we would have planned something to do in the interim.