question about auto insurance

Today i switched to liberty mutual because they are 30.00 cheaper per month than what i had, and it is still full coverage. My question is this. They have a little "tracking" thing that you can plug into your truck for 90 days. It records things like rapid acceleration, sudden stops etc to see how you drive. After the 90 days, the guy said i could get a 15% discount. He also said it in no way can go against you, only benefit you. What do you all think? Do it, or is this too much "big brother" type of stuff?

 

Bump

 

we did that with progressive, waste of time, had it in wifes car first, no discount,, had it in my tacoma, even the slightest stopping alittle too fasts counts as a too fast stop,, dont do it,,,,,,,you dont want them knowing how and where you drive,,

 

Thats all i needed to hear. Thanks.

 

Also did that program w/ Progressive. Got 12% discount. I agree the sudden stop metric is a little overzealous, I think it's something like greater than 7mph decrease per second... I got 2 "demerits" for the price of one braking once. I think the thing that benefited me the most is that on average I'm way below driving 50 miles/week -- and they got the data to support that.

The benefit will vary, worked out for me well.

 

Once you track the data for the first 90 days, are you done using the device? Or does it remain in your vehicle for as long as you wish to keep the driving "discount"?