it is working but slow;
Unfortunately, that is what WDS does. The bandwidth on the network is cut in half for each relay or remote. Since WDS only runs at "g" wireless speeds, when you have a relay and remote configured, the entire network runs at only 25% of normal "g" wireless speeds. This would be about 13-14 Mbps link speed. The "actual" throughput would probably be around 6-7 Mbps.
I was wondering if there was any traffic between the end node and the main station
It depends on how you have configured the main base station and remote. If you "allow" the remote to connect to the main, then the remote will try to "hop" over the relay, so there would be direct traffic between the remote and main.
If you do not "allow" the remote to connect to the main, then the remote must be allowed to connect to the relay. In this case, there will not be direct traffic between the main and the remote. The main connects to the relay and relay connects to the remote.
any toughts on this?
Avoid WDS if possible