I don't want to tire you with an exhaustive review about this watch (Polar RS300X), but I will try to outline its most important technical features. I assume that you are a serious sports person otherwise you don't need all the features of this watch. These combined features made me pick up this quality watch out of other branded sports watches or Polar models around an affordable price range (90-100 euro inc.VAT). Some of the features that I quote below are NOT mentioned (or better perhaps: are not clearly indicated) on the Polar official manual, despite being there for the user to enjoy! (you can download and read Polar RS300X user manual ) I have been using this watch during training/racing since 2009 and I never had any technical problems or issues with this model.
I've chosen Polar RS300X between other models after extensive market research, for the following reasons: