Unfinished, buggy and at times irritating
Let my start by saying how bad the combat mechanics are. I hate the "roll of the dice" style of combat, when your weapon fails to connect with an enemy standing an inch from you face it leaves you very frustraited. Then a pathetic vibroblade can take out a heavily armored droid in one hit. In my opinion combat should be like it is it Jedi outcast you do the shooting and sabering yourself. There's no sense of acchivement with Kotor and Kotor 2's combat.
Kotor 2 is riddled with bugs, prehaps the most annoying bug is the dialogue skipping bug. To fix the problem you have to exit the game and load your last save. Some of the movies have no sound, and make the game go to the desktop (as if you alt + tabbed out). Another annoying bug is that you can't move for a while after combat, so if more enemy decide to appear, you can't go anywhere.
Back to the story, kotor 2 doesn't really have a proper narrative, it's more of a load of crap mini storys put together. The is no real conclusion after you finnish the game, you ain't got a scooby doo what happens to any of the characters in your party, or how anything you've done in the game (ie kill sith lords) have actually affected the game. Maybe this will all be continued in Kotor 3, but i doubt it as they're making a cartoonish star wars mmo instead. very disapointing.
Kotor 2, despite it's many problems, is enjoyable (at times) to play though, if only to see how the crap story progresses and to develope your character, but after comepleting the game i was very disapointed with it all.
On the plus side, there are more ways to upgrade your lightsaber and other weapons than in Kotor 1, and to be honest, that's the only real improvemt on the original.
Some of the voice acting is abysmal, especially that of Darth Sion
All in all kotor 2 is very disapointing, it feels unfinnished, it's extremely frustraiting at times. It would be nice to one day see a Kotor 3 with a good story (like the original) and improved combat, but untill then i suggest you stick to Kotor 1.