Hi

I have four Mikrotik wireless access points, connected to the network with ethernet. They are using the same SSID and security profile, and are intended to provide good coverage throughout the whole office.

Is there any benefit to adding WDS? I have read that it can improve the speed of handovers when roaming between access points, but I am not sure.

No. Its only useful if you want to have another ethernet between an AP. Eg - Computer 1,2,3,4 -switch - AP -WDS- Client - Switch - Computer ,6,7,8, New AP etc.