Now that my Cobra is on the road I want to measure performance to see (roughly) where I stand. I have Dynolicious on my iPhone, but I understand the accuracy is limited by the sampling rate of the GPS unit in the iPhone. There is a newer version of the app that triangulates data from the GPS and accelerometer and claims to be more accurate, but the reviews say it can be buggy. The other option is to buy a unit like this
www.gtechprostore.com. $200 isn't inexpensive, but considering what I've already spent on the car... These are pretty focused devices with 10 MHz sampling rate GPS receivers, so they should be accurate for 0-60, 1/4 mi, etc. Any experience with either of these, or opinions?