I only owned 2 - my first, a 500, then I upgraded to a 2000.
I prefered the 2000, mainly because of it's expandability and the nice big case you could put everything in.
My 500 ended up with this octopus of cables and peripherals all over the place, and was a pain to transport and set up - The 2000 was just nice and neat, not to mention pretty tough when it came to lugging around to different meets/game parties/etc.