GTR's are fantastic cars as long as they are suitably cared for and looked after, much the same as any other car.
The problem is so many owners, particularly the younger ones, are so keen to own a 'GTR' they buy the cheapest example they can find, and as we all know you pay for what you get.
If you want a GTR, set yourself a realistic budget for a start, lay aside some spare cash for some preventative maintenance once you get it, (ie major service, timing belt, all fluids, water pump etc), then service it regularly with good quality oils and fluids and you shouldnt have a problem.
I have owned my R33 GTR for over 3.5 years and the car has been incredibly reliable and even in a heavily modified form it is a fantastic car to drive daily.