The problem is that obviously from the posts on PPrune many people in the UK don't understand GPS and its capabilities or limitations so it is very hard to get proper training to use it properly. Luckily I have done a lot of flying in the USA where GPS overlay approaches exist for nearly every instrument approach and standalone GPS approaches exist for nearly every airports with an IAP.
There is nothing wrong with using traditional instruments to back up the GPS but if they didn't agree I'd tend to follow the GPS for a number of reasons.
I still think it is nuts that the departure out of Gurnsey (if memory serves me right) has one dead reckoning a ground track to ORTAC. If one has a G430 fitted, why would one DR one's way there?!?!?!?!??!?!??!?!?!?!?!??!?!?!