I personally prefer Syrian's to own. I've had 5 Russian Dwarfs and all 5 of them were psychotic little bu**ers. Maybe we were doing something wrong.
However since joining this forum, I have totally been swayed, I'd not even heard of Winter Whites, Robos or Campbells, and I particularly like Robos. However I think if I were ever to own dwarfs again, I'd get them from a good breeder who should have started taming them, I think a lot of them in the pet shops don't get good enough start and turn evil! Mine did anyway!