Nikon F100 vs F5

The primary things the F100 sacrifices over the F5 are:
The F100 doesn't have mirror lock-up.
The F100 has a 10-sensor matrix meter instead of the F5's 1005-element color matrix meter.
The vertical release and extended grip are an option (MB-15) on the F100.
The F100's top frame rate is 5 fps compared to the F5's 8 fps.
The F5 has a self-monitoring shutter, the F100 doesn't.
The prism is not removable on the F100; it is on the F5, allowing waist level viewing and alternate prisms.
The F100 does not have a built-in eyepiece shutter (to keep extraneous light out when you're not looking through the viewfinder). Instead, it comes with a small plastic accessory that is easily misplaced.
The F5 has slow shutter speeds up to 30 minutes (you must override the 30 second cut-off with a custom setting to access them, however); the F100 doesn't (30 seconds is the max).

Benefits of the F100 over the F5 are:
The F100 weighs only 27.7 ounces, compared to 42.7 for the F5. (Those are the weights sans batteries.)
The F100 only requires four AA batteries; the F5 uses eight. The F100 also has an optional holder (MS-13) that takes two CR123A lithium batteries (a wise option if you plan to use the camera in cold weather); the F5 does not have this option.
The F100 has more flexible bracketing, allowing 1/2-stop adjustments in addition to 1/3- and full-stop settings.
The F100 has a user-selectable function called Closest Focus Priority, which defaults AF to the sensor that sees the closest subject (more on this later).
The AF sensors in the F100 briefly light in red when selected and are very easy to see, while the F5's AF sensors are black LCD superimposed over the viewing screen, which can be difficult to see in some lighting and with some subjects. Moreover, the F100's E-type screen uses the same AF sensor technology, while the F5's original E-type screen does not show the active AF sensor.

Minor things that are different on the two cameras:
The F5 has a secondary LCD display, which shows the ISO setting all the time. Bracketing, custom functions, and lock settings are shown on this secondary LCD, as well. The F100 has only one LCD, and all settings are shown on it, although some settings only display when you're adjusting them (ISO, for example).
The Dynamic AF control is on the back of the F100 along with an AF sensor lock; the control is on the top plate of the F5 and it's not as convenient to lock the sensor.
The F5 has a lock to keep the power from accidentally being turned on; the F100 doesn't.
The F5 allows manual rewind and has �safeguards� to keep from accidentally triggering rewind; the F100 doesn't.
The F5 syncs to 1/300, the F100 to 1/250. (Note that the Guide Number is reduced at the 1/300 setting, though.)
The F5 has a separate multiple exposure control; the F100 simply makes it one of the frame advance settings.
The F5 features a 100% viewfinder, the F100 96% (the F90x/N90s is approximately 92%).
The F5 lets the user set the exact self-timer delay from 2 to 30 seconds; the F100 has only four selections (2, 5, 10 and 20 seconds).
The F100 meters from EV 0 to EV 21 in center-weighted and matrix mode; the F5 from EV 0 to EV 20.

---------from Thom Hogan's website