This game is everything a bad PC port could ever hope to be. A quick break-down:
+Increased draw distance from other versions. Very nice!
+No HD textures, but improved filtering on PC helps a lot.
+Runs well, no more slowdown as is present in console versions
-No analog support. Acceleration and steering are either on or off, even with an analog stick.
-The digital steering isn't very good, either. Crazy drift is practically broken on a keyboard.
-The configuration menu only saves half of the specified settings
-Need to make registry modifications to get controller/resolution settings to work
-Doesn't work in full screen mode, regardless
-There are only 4 supported resolutions, topping out at 720p
-Severe audio mixing problems -- SFX volumes are all over the place.
-Original soundtrack was replaced with some REALLY UNFITTING music.
-Different voice actors! Somehow even less enthused than the originals.
-Sound clips for all voice actors and announcer are EXTREMELY low quality
-Audio clips are now spammed like crazy. Expect to hear "Taxi!" until your ears bleed.
-UI elements are very blatantly untouched. Extremely grainy/low-res, even at 720p.
-All identifiable buildings, such as KFC, Pizza Hut, and Tower records, have been removed.
So, in a game that's positively regarded for well-done arcade-style gameplay and control, a fantastic soundtrack, and a slick visual style, this port managed to achieve...well, almost one of them. The UI looks very bad, but the actual game behind it holds up fairly decently. Also, a quick search for 'Crazy Taxi PC Soundtrack Mod' will give you a way to restore the original soundtrack. The terrible audio mixing will still hamper your ability to enjoy it, though.
This really isn't worth your time for anything more than a dollar or two. Pick up a dreamcast emulator and play it that way. It's a pain to configure, but at least you'll get analog steering. How SEGA thought it would be okay to release a game that revolves around weaving a taxi in and out of traffic at top speeds without any fine degree of control is beyond me.