RB, Bridge or Router operation mode

The bridge with an intermediate point, distance is 30 and 40 km.
Equipment: RB532+R52H-> RB333+2xR52H-> RB532+R52H,
what operating mode is more preferable, - a bridge or a router?
It is necessary to reach the minimal delays, the traffic is - 5-6Mbit, 600-900pps.

Sancho -
Personally - I have always found that routed is faster than bridged. The only exception would be an extremely small localized network.