Looking at getting a Garmin. Amazon have fr310XT with HRM for about £125 at the moment, which is a big saving. They have fr10 for about £75. Anyone use the 310 just for running? (I won't be using it for cycling or swimming.) I realise the 310 is a much bigger, heavier thing. I am tempted by the battery life, as we sometimes go for long walks and my phone runs out of juice after about 4 hrs with GPS "walkmeter" app. I gather the 310 has a "get me back home" function . Also the 310 is properly waterproof. And the included HRM is a good £50 if bought as an extra. I have looked at the "rainmaker" reviews, but just get more confused. Any advice welcome. thanks.