paced tcp suffers from more timeout?

em... this seems to be a problem.
SACK likes the loss of an interval of packets instead of a scatter of packets even if there is a few scatter of paced packets... The loss of one burst of packets can be recovered by one SACK but the loss of 4 paced packets have to be recovered by more than two SACK...
This often leads to more timeout for paced flows.

default queue-limit for each queue is 50pkt

em... it's not unlimited by default. So, packets may be dropped in such queue if
1. the window is large.
2. the side bw is similar to the core bw