I tried them and got a bunch of belts cheap. Order extras.
The one thing I've noticed is that the belts are a little stiffer and slightly smaller in circumference, which means they hold VERY tightly, which is a good thing, but also puts a little extra stress on the handle that engages the drive, and on that pin that holds the handle in place. Bring spare pins / etc.
beej67, Checkered Past, 1980 32' Pearson 323, Panama City FL