You're right about the overkill, unless you're desert racing. The 160's big feature is that 10 hz refresh rate, which is killer for use on the track, although you can get even faster ones.
But OTOH it comes with versatile charging options (cig lighter or any USB connection), it does data logging (nice for picture georeferencing) and it is one of the best for use with any Apple product, since not many are.
I've purchased other cheaper loggers and BT GPS units, and frankly although they do fine with the GPS reception, I need PC software to set them (and of course the utilities don't work in Win 8) and they don't work with iPhones unless I jailbreak them. Not worth it.
So, depending on your needs, maybe too much, but then again, aren't most things around ex-po?
