Strengths: Much lighter than it looks, easy to use and very accurate. Shop around on Net for bargains, got mine for £140, well worth it.
Weaknesses: Sometimes takes a while to find the satelites especially where trees are about. The software is not Apple compatable, although I'm not that bothered as looking at graphs is all a bit geeky for me.
Overall: Very pleased with it. Am finding it much easier to pace myself on long runs. It also helped me get under 40 minutes for a 10k. Something I've been trying to do for 5 years!!