Not exactly. If the two back to back access points are on different no-overlapping channels (i.e, 1,6,11), they can transmit and receive simultaneously. Therefore, they are full-duplex and do NOT suffer from the 50% bandwidth reduction caused by simplex repeaters. This is the way I do all my repeaters. Well, all of 2 of them as I really don't like to use repeaters where a bigger, better, and usually uglier antenna will do as well or better.
Why does it only rain on weekends?