Modern and complex aircraft are all fine if you have experience, but in a flying school you need to have some good basic trainers as well, without all the added complexities of GPS and multi mode PFD's.
Teaching people to fly is 90% phsycology. A person needs to be in the correct environment. The basic flight instruments and a VOR are all you really need to start with. Anything else is superfluous. Any decent school/club will not stop teaching you just because you have a licence. It is only a licence to learn, it does not engender any particular competence apart from the very basics.
A good set of basic trainers for PPL teaching, that leads on to more complex machines once the basics have been learnt PROPERLY. This is why I am totally against teaching GPS from the beginning. Yes it is a fantastic aid, but human nature being essentially lazy. How often would it get Surreptitiously turned on during a QXC or solo Nav? That is not the point of the exercise. COmpasses, stopwatches and even slide rules are a vital part of the armoury of experience that we all should have.
Basics first, then we will teach you how to operate the a/c and all the other systems. This causes problems because once the skills test has been passed, we very rarely get to fly with our ex-students as they want to be rid of us and get some 'freedom.' An IMC course is usually the only opportunity we get to really start showing what capabilities there are in light a/c.