Garmin Forerunner 305 Review

When it works it is, in theory, quite accurate as it uses GPS technology.

Its just not ready to be a watch yet, in my opinion - they need to get the technology smaller and working better before they launch this sort of product

Having a GPS watch in principle is great, but it constantly seems to lose signal so it essentially just guesses how far you've run - not very useful

The Polar watches are much better - they dont use GPS technology instead they use some sort of movement sensor.

I find the Polar watches much more accurate, less bulky and generally better put together (hardware and software)