The amount of time that any migration of a server (workload in our terms) will take to migrate is not something we can calculate for you. Since there are many variable we cannot account for we only suggest that you try an Evaluation license and test for yourself in your environment.
For example, things like if you use our WinPE 1.5 (the default) or the second WinPE 3.0 which comes with the target physical Take Control zip file, these can change the speed as newer drivers are available in WinPE 3.0 then in WinPE 1.5. Also your connection may have QoS or compression or other elements like switch settings which may affect the speed you would get.
For the most part PlateSpin Migrate does not throttle any speed of the migration unless you configure it to do so, however the original (source) OS has the ability to limit how much bandwidth it gives our process, your internal network on both side and the WAN link can also affect the speed, and there is also the speed of disk read on the source and write on the target which can affect the speed of the transfer you would see.
In short, grab an Eval license and try it yourself on a test system. This is the best way to really to find out how fast you will get in your environment.
PlateSpin Support Team