If you don't like the boat, there is a direct bus to MK.
No, we didn't find the boats slow at all. They were wonderful and never crowded (except for after the fireworks, when everything was crowded!*LOL*). Besides the large green boat, there is the smaller blue boat that goes WL/CR/FW. It runs 6:45am - 10pm and there are generally 2 running, 1 clockwise and 1 counterclockwise. The ride from WL to CR is less than 5 minutes. You can take this and walk or monorail to MK.