I started out in 3d and used it for the first month or 2 that I played UO. I was having hella problems with getting it to run smoothly and so I tried the 2d client and fel in love. ;) I had ALOT better performance with 2d.

The puter Im on now will run either, but I still use 2d with most of my chars. I usually get on in 3d with my Smith to sort out my messy boxes...gotta love the re-sizable container gumps.