It adds information, but it also influences the car's behavior. So it's technically speaking not a favorable decision to make. At least not from my point of view.
I am also a whole lot smoother without those 'canned effects' than I am with them. Actually, I can finally drift with ease and control the car freely. Even in hairy situations I still am able to maintain control, whereas before it would be an instant spin. Especially in v0.22 when the weight transfer effect depicted the angle the wheels would point at.
I personally believe it would be better to redirect some of this info (kerb rumble, road noise and bumps, etc) to Simvibe instead and let the tactile transducers produce kerb rumble and road bump information. Slip is useless information as you can visual see the slip and you can feel it without the 'weigt transfer/seat of pants' effect. You only need to feel where you're at on the slip curve to get a sense of what the car is doing.
Say if you're at the peak of the slip curve and you feel a decline in force from the steering wheel suddenly, than you know the car's losing traction at the rear and your eyes will be able to tell you which direction that is... if you didn't feel already where/which direction the peak of the slip curve walked of to that is.
Each his own. And as long as the simulation games give us the options to completely tailor our effects mix to our liking, I'm fine with anything being in the game. Everyone should be able to run their game the way they want after all.