About a year ago, I was offered an F5, at a price very near to what I could get an F4S from KEH. After only a short time, I decided on the F4S. One thing I like is that you can see all the settings without powering the camera on. Other than that, it is well balanced, despite the weight.
If you will only be using autofocus, you might find the F5 to be a better choice. If you want to mostly manually focus, I would suggest the F4S. Honestly, there is little to no difference in the metering, and you actually get a few more options using non-chip (no electronic sensor) lenses on the F4S.
I shoot more 4x5 now than 35mm, but when I needed to shoot 35mm, the F4S is the first body I grab. I also have the waist level finder, and several different focus screens to choose; accessories can really improve your shooting options.
Gordon Moat Photography