Also worth mentioning, GPS has a lot more functions than just "follow magenta line", which is actually what most owners/users of it do - sadly...
Even the oldest GPS gives you the most important information: position (latitude, longitude), ground speed and TRUE TRACK. In my opinion, flying dead-reckoning (as IO540 suggests) across the Europe is stupid. With GPS (or radio-navigation if you fly VOR to VOR/NDB) you can fly approximately great circle tracks, while with dead reckoning you have to be a magician to fly calculated headings and get no drift whatsoever. And if you forget to check your average Directional Indicator every 10 minutes, you might end up flying to origin instead of destination after an hour. From my experience, flying true tracks indicated by GPS instead of compass heading, calculated with various roundings in the process is much much better and accurate, it gives you very little drift. Sadly, many instructors don't teach various GPS techniques, but only D-> and follow magenta line until you see the destination airport.
My opinion on GPS and all the new technology: if you have it, use it. That of course doesn't mean you have to stare into your shiny new G1000 from rotation to flare...
You should always however maintain reduncancy in navigation: if GPS dies, you always have a backup one. If even that fails, you have VOR/NDB/DME and if all hell brakes loose, you still have good old DR. If you only know how to use DR, havent tracked a radial/QDM/QDR for ages and GPS is the worst sin on Earth you could possibly commit, then whenever the wind forecast is wrong, you will get either lost or at least enormous drift.
My 2 cents....