i've recently bought a navman s50. i've found it to be reliable and very simple to use. i've not yet read the instruction manual and in all honesty there isn't much need for one. the sat nav itself calculated routes quickly and if you manage to take the wrong turn it redirects you with ease. the built in bluetooth handsfree set is great, no need to clutter your car with electronics. all in all a quality piece of kit for the price.