At the moment, mid is the one that feels most... standard.
It's another bridge, really. Two flanking narrow routes, mirrored height advantage, and a point over health. It's solid enough, but... formulaic. Like you're reading off a list.
The shack is a nice idea, though give an all-class route to the upper levels, since soldiers and demomen dont need more of an advantage. Maybe sawmill-style narrow routes from the side high ground? and balanced cover on the upper layer of the shack? You then have three levels- the upper shack, for defending the point, or covering an attack, (maybe with no LOS to the point itself?), the middle bridge with the point, and the lower level with health?
The problem i see with this is making mid harder to re-cap. But, with the ramps, it shouldnt be too hard to clear out a soldier or sentry. Plus, the three levels thing is (comparitively?) unique?
Half the people don't make comments because they think they don't know what they're talking about (which isn't even the point about feedback)
There you go. Enjoy, with a pinch of salt, of course.