It definitely helps, I've seen it and it explained a lot - what I still don't understand is, for example, if I wanted to export the maps for the last example he gave out of 3dsmax and have it work correctly in Maya - how would I do that without Handplane?
You should read through the beta thread or the current support thread for examples of what to expect for each output. There are limitations with some engines and shading errors are still possible with unity (in forward rendering mode, deferred looks perfect) and probable with unreal.