I want to buy a GPS watch as a gift for a young runner, mainly for her to track her summer xc mileage. I know nothing about these things and need advice. The NIKE one I'm looking at is more reasonably priced than Garmin, but she doesn't wear NIKE brand trainers. So would that mean she can't use the shoe chip and how much will that problem affect its usefulness to her? Or can you dig a little hole in another brand? For example, if she runs on the old treadmill at the Y that doesn't track mileage, will she be able to use the watch for that purpose if she doesn't wear the chip in her shoe?