I think the boat is the fastest, simply due to the lack of a wait. The boat is a non-stop trip. We just missed a boat on Sunday (got there as the Capt. was roping everything off) and only waited 5 minutes for the next one. You get a good view of the GF, Poly, Cont, you float over the Water Bridge... excellent.
Be prepared to be STUFFED at WCC. And entertained.