With all the latest patches in, Morrowind runs more smoothly than when it was first released. Current computers run Morrowind without a problem, the computers that existed when MW was first released were strained by it. The only slowness is the game itself - Morrowind isn't something you can run around very quickly in, (unless you have a certain pair of magic shoes). There's a lot of freedom in that you can do what you want. There is a main quest but there's never any urgency to push you into it if you don't want to do it. I never really cared a lot aboutthe main quest with so many sidequests to do.
I made a warrior and he became head of the Fighter's Guild and the Rendoran Housefather. He is also an Imperial Dragon. I also had a Mage and was half way through with him before I left the game hanging because of other distractions. (Have all my saved games backed up for the day I return to it again.)
At first, MW feels like a challange, and then it becomes too easy. But the expansion packs do add challange. The MW world is huge and detailed, but the NPCs are lacking, often stiff and samey - I hope they improve this in Oblivion. But overall, the game world is a good place to get lost in if you feel the need to get away for a while from this one.
I don't know if the triple pack still has this problem - MW sometimes shuts itself off (close to desktop)in the middle of a game , so always save often. It happens to me if I play it for more than an hour or more, but for others it happens more often.