Well Dean, it might not be a MoTeC or DL1 or a $40,000 Pi system, but if you can't see the advantage of something like this, you're blind!
Lap timers tell you when you're faster, data aquisition systems tell you why you're faster. The problem is that Daq's cost about 5 times simple lap timers... so you get what you can afford. However, I'm so impressed by the results of that Traqmate system, I'm thinking the extra $800 for it might be worth it, over just grabbing a hot lap timer. But at the same time, if you try a new line, and you're 2 seconds faster, chances are you just found your new line... a simple lap timer does help.
Also, I don't think anyone in the thread so far is under the impression they're covered by insurance on track. I know if the WRX gets wadded up, it's getting trailer'd home and salvaged into a new shell.