High-Level PCs Only, Please
The most important question is whether or not Tribunal is worth the $30 price tag for those that are already playing and enjoying Morrowind. If you have a high-level character that is either finished with the main quest or is at least level 30, then yes, Tribunal provides hours of additional entertainment as the fights are more difficult than those in Morrowind and the storyline stays true to the overall feel of the Elder Scrolls games. However, if you have a mid-level PC or are just starting out in Morrowind and are not sure that you'll want to play another 20 to 30 hours after finishing the original game, then it's a much tougher sell. This is an expansion that adds a few new wrinkles, but is more or less an additional city (Mournhold) that is full of tough fights and quick deaths to the unwary.

The Obligatory Tweaks
Tribunal is described by Bethesda as being more of an "add-in" rather than an "add-on," meaning that the new stuff as well as the technical enhancements simply becomes part of the huge world of Morrowind and not just an extra area to explore after the main quest is complete.
Some of those technical enhancements include a new journal system that is more user-friendly than the cumbersome one in the original game. Quests are sorted between completed and active, and while it still gets a bit unwieldy, it's light-years ahead of the old system and helps to keep things a bit more organized. You now have the ability to annotate maps, which again adds to its overall usefulness; it's easier to find your way around with the expansion installed.
In addition to the new journal, all of the extras included in the latest Morrowind patch are in the expansion, such as health meters for monsters, and so on. Lastly, by installing the expansion, it makes Morrowind a much more stable program. In our original review of Morrowind, the game was extremely crash-happy when using an SB Live sound card. All of those problems vanished upon installing Tribunal. (It should be noted that Morrowind still had a tendency to crash even with the latest patch.)
Where Are You Going?

The dreaded Orc Warboss.