Time 2000 is probably the hardest one to find out of the bunch. Middle Earth comes up fairly frequently, space riders not quite as much.
None of the Atari pins are particularly exciting to play, although Time 2000's layout is certainly quite different with the way the four flippers are arranged.
Atari pins aren't seen enough in working order for most folks to gauge how they play.
At *some* point (and once I find a Time 2000 or Time 2000 cab), I'd really like to get all of mine up and running and line them all up together at a show.