The Thrifty site is about a mile and a half I would guess. We did not have to wait at all for a shuttle, it was there waiting on the lower deck. We did join the Blue Chip program which was a blessing because it was crowded last week. We were second in the Blue Chip line. When we returned to the airport there was a sign leading you to Thrifty, which was a huge help because that was out first time driving in the area. The bus to return you to the airport was waiting for riders to board, I would say that took about 20 minutes in total, waiting and the drop off at Southwest.
All in all it was a good experience, I would use them again!