The floating wedge allows for movement upwards when splitting a piece with a knot or branch or twisted grain - allows the wedge to follow the grain instead of having to slice through the grain to keep the lower split at the same height. The downside of a floating wedge is that it may continue to creep upwards over time, resulting in the the lower splits getting larger and larger and larger. This happens when the lower split stays under the wing keeping it up a bit, then the next one pushes it up and stays under pushing it up a bit more ..... Eventually you need to toss a small one in there to clear out under the wedge and let it drop back to the original setting. It makes for easier splitting and cleaner splits too.
I was very impressed with how well the splitter centered the rounds. The slight slope on each side was enough to bring the rounds into the center = every time. My home made splitter was made with a deep trough for that reason - but my slopes are much steeper, making it a much higher lift to get rounds in. Seeing that in action - I
He sure made a heck of a lot of firewood in the 12 minutes I watched. Clearly he has had practice tossing those rounds.