I am a Mac person (19 yrs). That said, I use a windows machine and a mac to create runtime solutions. I network the two (and other machines) together so I can pass FM files. I then use a 2 port KVM switch (iogear) so I can use the same monitor, keyboard, and mouse.
I build in mac, move the database over to windows and go through every single item (fields, scripts, fonts, layouts, relationships etc.) one by one and re-build on the windows side. I originally started building in windows and moving to mac and while that was the best for conversion, working in windows is like riding a 10 year old donkey when you have a 2 year old throughbread chomping at the bit in the next stall.
Filemaker pro developer disk has both windows and mac versions on it. It has to be installed and run completely separately and you have to have 2 complete and separate versions available for your users.
That's some of my experiences.