What are the pros/cons of installing glass doors over a whirlpool tub?
The metal guide track is only annoying if you really don't like the looks. that is a personal thing, but every tub with doors has one and millions of people live with it.  The vibration from the jets will not adversely effect the glass doors at all, especially if you select a quality door unit. I prefer to install suspended type doors like the Kholer or Sterling. They suspend all the weight from the overhead bar so there is no weight on the bottom guide. they operate very smoothly and are easy to keep clean, especially the ones with treated glass.