I've had the #4. The 1/2000th of a second LCD tester, for a bit over a year, and have been using it on most of my shutters during that time.

It's really quite simple: set the camera up in your darkroom or studio, on a tripod.
Opposite the camera, set up a light ( I use a portable light table, about 10" X 12"). I set it up at a distance of about eight (8) feet, but use your own judgement.
Focus the lens at infinity, directly and square to the light source.
Eliminate extraneous light; I use a big changing bag: I peek the lens through one of the sleeves, and wrap the bag around the camera, then enter through the unzipped bottom.
For a focal plane shutter, I use a small, light tripod behind the camera and with masking tape and a small stick ( I use tongue depressors) set the receptor at the centre of the shutter, about 1cm from the curtains.
Zip the changing bag up most of the way, leaving the wire to the "unit" run through the small opening.
Turn off all the lights in the room, except for the light source directly in front of the lens.
Set the shutter at 1/30, turn on the tester, and fire the shutter. Record the readings. Repeat three (3) times.
Set the shutter at 1/60, turn on the tester, and fire the shutter. Record the readings. Repeat three (3) times.
Set the shutter at 1/125, turn on the tester, and fire the shutter. Record the readings. Repeat three (3) times.
etc until the top speed has been tested.

Then, repeat the procedure, from the top speed ( repeating each test 3 times) until the bottom speed is reached (usually 1 sec.)

Then, repeat the procedure, from the bottom speed ( repeating each test 3 times) until the top speed is reached .

This will give you a good idea of the precision of the shutter, and a good judgement of how to adapt exposure at each shutter setting.

The test system is accurate. The test unit is accurate.