I work in a brewery in production. I work around loud machines in a wet environment and time activities throughout the day. With its vibration features, the Casio W-735 was a great watch for me. However, when I heard about the GD-350, with the one touch countdown timer, I thought I'd give it a try. From a functional standpoint, I liked the GD-350 a bit more and started wearing it every day.
However, I missed the superior button feel on the 735 as well as it's more compact size. So I decided to cram the GD-350 "movement" into the W-735's case. To make it fit, I had to remove a small amount of material from interior of the 735 around the light button - I did this with a Dremel and a razor blade.
The result looks rough (ugly), but it works great! I have all the functionality of the GD-350 with the reduced weight and size of the W-735.