Wow, that was quick! Got them this morning, and on their standard delivery.
From my initial experimentation, I would say that the two biggest problems except for the lack of side protection for the trigger finger and little finger are:
1. The difficulty of bending the hand back 'through the thumb' to the elbow, e.g. when pulling back from a right-side oberhau through a moulinet (not sure of longsword terminology) to a left-side false edge oberhau. Does that make sense?
2. The previously mentioned plate at the end of the thumb. I have found that this makes it very difficult for me to get a proper thumb grip on the handle, but I think that this could be fixed by 'shortening' the plate. Has anyone tried this?