This is useful for me too. Bought my 520 on Thursday, bewildered by three more buttons than on my 500, having to say what kind of ride I'm doing, etc. Used it at the weekend, forgot to press STOP a few times when I stopped (didn't need to with 500), and accidentally reset the timer partway through 600km, but I was able to keep it charged up off the dynamo. Currently use my etrex to plan courses, but I will give the 520 a go, heeding the advice here.