This is one of the best upgrades you can buy for your TT-01. It must be used with the 3Racing swing shafts, which may put you off since it will cost quite a bit for two sets front/rear, but it really is two upgrades in one that will improve the handling of the TT-01 tremendously. It can be (and was, in my case) used straight out of the box for drifting..it even comes with bearings! It also looks very nice, it may be a moot point since you won't actually see it once it's installed, but until you get around to it it's very impressive to look at.
Getting LSD's in your car will be the best thing you've done to improve the handling, I'd recommend this before getting new suspension.