Ellis -
If you like split-image screens, try the Nikon type K or type P screens for the F4. Type K has a split-image surrounded by a microprism, and type P has a 45-degree split with a microprism and vertical/horizontal lines. I was happy with the standard type B screen, but used the focus confirmation frequently.
The F4 is a great camera, the traditional control layout is really nice if you prefer dials over buttons and menus. It's bigger and heavier than the F3 (obviously), but has the built-in motor and AF. It just oozes quality and feels like a rubber-coated brick. It's not the best choice for action/kids/sports as the AF system is not the fastest, the F100 would serve you better if you shoot a lot of action and want to use lenses with VR capability.
I sold my F4 as I didn't really need the built-in motor drive and it was quite a bit heavier than the F100. However, I did prefer the control layout of the F4 and it felt a lot more solid and reliable than the F100.
I also have an F3 and F3HP, and they are great cameras as well.