We have one 1310 (root) at the office feeding two 1310 (non-roots) down the road (1/4 mi). One of the units is much slower than the other and we can't figure out why. Both have the same signal strength and snr.
Signal Strength (dBm) -52
Signal to Noise (dBm) 34
Are the signal stats good enough?
We rarely drop a packet and get <1 ms pign times but files, pages and other things seem to load.
The non-root bridges feed two switches on both ends. One is a gigabit and the other is a 10/100.
I'd switch channels and see what happens. But I don't know what exactly you mean by "slow".
Also, it could be a duplex mismatch at the AP to Switch connection. I ran into this on a mesh link the other day where the only fix was for me to hard set the ports to 100/full for the trunk link to the root ap.