Schuie Driver,
I would not call it unlimited vertical, it will keep going up, but it does get slow about after 700' or so. I think the two big gotcha's were covered by Mike.

tmproff,
Worked too much with my Magic to try the 12.25 x 3.75 prop yesterday, but will give it a try this weekend. Have used it on a US40 with good results before.

Ed M.