Strengths: Amazingly accurate in terms of all the functions I use distance, time, pace, mapping etc. It takes a bit of practice but we are so use to using technology intuitively without reading instructions that we are spoilt. With a little practice and patience the 405 works brilliantly and, in so doing, is an excellent motivator. I used mine to pace me through 9 consecutive PBs over different courses and distances. What more can you ask?