All I know is that I have had a devil of a time getting Apache to run PHP on all of my different Windows machines for development purposes. IMO, Apache is not designed to integrate well with Windows - or at least get set up by novices under Windows, so far as I can tell. In the mean time, the server I mentioned is designed specifically for a ME/XP/2K type environment and is quite easy to install. For novices, developers, etc. under Windows, I think it's much easier.
[Edit] - one other thing, I only visit every few weeks. But I always seem to find a bunch of folks having trouble getting PHP installed under Windows, whether it's Apache, IIS or PWS. I counted three this morning on the first page alone. So I don't think it's just me.