D:OS is a good game, but it appears that D:OS2 will be improving a lot of the things that didn't work so well in D:OS.
I know I was never able to play KOTOR because I played KOTOR2 first. Play D:OS EE now, and enjoy it while you can.
Hopefully the differences won't be too alienating: even as the sort of player who likes the "ooh shiny" of new stuff, I've gone in the "wrong direction" several times and thoroughly enjoyed myself, even playing DD only recently after starting the series with Ego Draconis. A bit retro, but fun.
Same with The Elder Scrolls, started with Oblivion but had a lot of fun with Morrowind afterwards too. I think one of the few times I really didn't enjoy revisiting an older game was playing Half Life after HL2, though I didn't really like HL when it was first released anyway, so I don't know why I thought that might change!
And where D:OS is concerned, I prefer the classic over the EE, though as I've said elsewhere, that's mostly down to the voice acting.