I had a 97 ZR 580 EFI. EFI was great when it worked well, you never had to worry about temperature and it always started on the third pull no matter how long it had been sitting but if anything goes wrong with the electrical system you really have to know your stuff to fix it. Overall I really liked it though. That F7 should be blast to ride!
Get an EFI, they are a lot less hassle. The new systems have came a long ways from the 580's...the battery type EFI's were a piece of crap. They always start, and you dont have you clean your carbs at the start of the season every year.
Efi will run in any type of weather, cold or warm, and you never have to adjust the jetting!! Carb sleds usually run better the colder they are because it leans them out, but the warmer it is they get richer. Or is it the other way around? Go for the FEI, but if a good deal on one without it comes along grab it!