Routed network speed

I currently have a very large bridge network, speeds to clients are not an issue for internet usage. However, I believe my speeds should be going faster. As such I am testing an experiemental setup all routed (no bridges).
I setup a small experiment simulating a section of my actual network.
I am using three boxes, one is a AP only, 2nd (dual card AP/Station), 3rd Station only)
1st AP ------------> 1st Station / 2nd AP ------> 2nd Station
10.1.0.1 ------------> 10.1.0.2, 10.2.0.1 ---------> 10.2.0.2

all the routes are correct as they can all reach each other.
Speed test from 1st AP to 1st Station, 5.5 Mbps TCP
Speed test from 2nd AP to 2nd Station, 5.8 Mbps TCP
Speed test from 1st AP to 2nd Station, 1728 kbps TCP

Now I understand there should be some drop but this seems excessive. Is this typical of this type of setup or should I expect more speed?