I use the Z1 Analyzer quite a lot, to track how I am performing as a driver. It does give some useful hints out of the box, like lockups, wheelspin, over understeer and all that. This definitely is a nice idea, and it does give a good starting point on where to improve. A nice feature it has, is that other people often upload their laps, so you can try and compare yourself a bit. This really helps, because you get to understand the driving of other drivers. I usually use the software to refine my breaking points and driving line.
