I have the 23 and like said it is a solid hull!!
I am not sure about the 21, but the 23's have to have trim tabs, it really makes the boat perform in seas!
Also on the 23's I hear that they have a issue with the floor getting soft in the rear? Mine has one spot a little soft but it is going to be years before I am ever going to have to do anything about it.
They are a heavy boat that adds to there stable performance and have a 20* dead rise like the V20.
Just make sure when you are looking at them you ck well, they are a wood core boat, there is a lot of wood from the bottom of the hull to the floor, transom, stringers.
Hope that helps, let me know if you have any questions.
http://www.youtube.com/watch?v=5r9ey2D2KRU