Nothing wrong with using a GPS - IF you keep a check on its results and gross error check it, and have a map handy if it goes wrong. Never assume that things electrical are producing accurate readings.
One thing super-reliance on it does encourage is a change in the decision making process - with much of the navigation task taken away from you, there is more time to get yourself into deeper trouble if the weather is bad. Also, as it is very accurate, there may be more people in the same airspace looking for the same spot - also bad in poor vis.
Phil