I like it more than any Mario Kart, mostly because of the skills and the pick-ups, as well as customization...
Even with the slowdown, kinda crappy 3D graphics with 2D kart sprites, I've beaten this thing at least a dozen times in story mode and play it still occasionally. I like being able to choose a playable character after you beat the game, change it's color, edit its stats (like speed, acceleration, handling, etc), and be able to play it in grand prix, versus, and time trials.
I big reason I like it more than Mario Kart (which I have for DS but have played SNES and GC versions), are the pick-ups and skills.
Before the race you can choose one of several skills that you can use when your skill-meter fills (speed-boost, steal item, power up what you have picked up, etc. etc.), and then there are the pick-ups.
Pick-ups you can pick up to three things, or three of the same item. Most items will power up when you pick up say, two or three fireballs. One fireball is like a green shell, two is like a red shell, and three will go through the entire track and hit everyone eventually.
There's also ice (basically a banana as the first one), which gets really powerful at "level 3" where it'll attack everyone and make them spin around.
And to name a few more, there's speed up, barrier, and ultima.
Ah well. I kind of wish Square would make a better updated version of Chocobo Racing (but only for DS, I don't think it would be worth it for PS2 or GC...)