Eventually got my hands on a Waterman Man 100 and am most impressed. Apart from the monster size of the pen the build quality and general feel are exemplary, pen making at its very best. Here it is alongside a Parker 51 to give an idea of the size:
The design of the Man 100 is very traditional, reminiscent of a 1920s English lever filler, but it isn't English and it's a cartridge/converter filler. The classical appearance of this example is enhanced by the colour, Black with Gold filled trim.
I have to admit that it is a bit of a 'show off' type of pen but it is much more understated and has a certain dignity that such as the Montblanc 109 lacks. I mention the 109 as this was apparently the pen that Waterman decided to 'take on' with the Man 100.
When the pen was launched, in 1983, it was listed as the 'Le Man' 100' but this was rapidly anglicised to 'Man 100'.
The Man 100 is now for sale here