I wouldn't say it's useless, just that I don't use it. Combination of our carpet (only unrolled every two weeks Oct-Mar), my car(s) and my driving style I always end up needing to dial in more steering (always have an on-power push) and one thing that helps is heavier fluid. I like the medium (they call it "heavy") CRC fluid with the white cap. I've also had good results with the Losi Hydra-drive fluid. I've never had a bottle of the CRC "extra heavy" (always out of stock it seems) but will try it this season and see what I think.
Scottrik