multiple base stations & seamless roaming

[CompLogic]

The W52P will not roam "seamlessly" or "transparently"

You can register 5 handsets & SIP accounts, but can only have 4 active calls. Using a repeater cuts the active call channels in half from 4 to 2.
I don't understand the thought process behind this design at all.

The handsets have to disconnect from one base station to register with another base when "Best Base" is selected on the handset.
The handsets wont swap when on an active call so if you leave the reach of the base you are currently connected with the call will drop. Even though you are standing next to a base station.

Uniden Honeycomb is the only system that I have tested that works "seamlessly" and "transparently". Although they are significantly more expensive they simply work.
EXP1240B (base) EXP1240H (handset)

The base stations have built in controller software communicating through Ethernet and pass the handsets between each other.