Other reviews mentioned it was slow to acquire a sat lock or was dodgy under trees. I have used it successfully for 3 months in and around Edinburgh, within mixed deciduous woodland and under overcast skies. It can take up to 5 minutes to get a lock but I am usually stretching so it is not a problem for me. As a comparison, my Samsung phone is a bit quicker to get a lock but still takes a minute or three.
The range of functions are fine for me and the display options good enough and easy to read.
Not put it's waterproofing to the test yet. Would be five stars from me if there was a way of uploading the data.
Mine only came with a quick-start guide and not a full manual. You can download a copy from the Times website so no huge drama.