Hey Mark, I have and I really like that stuff. It absolutely will not absorb water and eliminates one step in building a lure. Not sure about bouyancy but I feel that it is very close to poplar wood. It is easy to shape and sand.
I am working on one right now. Right now it is so cold down here and in my un-insulated, unheated garage that I have not even placed the belly weight in it yet. I am trying to learn one of Littleriver's methods of painting so since I can't stand the cold, I jumped the gun and started painting on this one before it was really ready.
One other thing that I found about this stuff, when I first started using it I was worried that with it being so slick that my hook hangers would pull out under a load. So I made two haywire twists 1 1/8 in long each. The second wire was inserted thru the loop of the first one before being twisted so that they were linked together. I then took two small pieces of the PVC drilled a hole in each piece and inserted the wires in the holes. I then applied thin CA glue to the wire where it entered the hole and let it set overnight. The next morning I tried pulling the wires out They wouldn't budge. We have a body builder where I work and I took it to him and asked him to pull it apart. He couldn't do it either although he did succeed in elongating the two eyes of the hangers. So I did find out that this stuff really gets a grip on wire using CA glue.
Here is a pic of the one I am currently working on.
John
http://s253.photobucket.com/albums/hh72/JBlaze1952/PVC%20Crank/