Need help: FZ100 or FZ40 or....

Hello,

I've reading most of the threads concerning FZ100 and the image quality. But I think its very difficult to decide and I need help. First I read the forums in germany and a lot of people give their FZ100 back because of the IQ. But here I saw a lot of great images. So what should I do. Buy the FZ100 an hope the IQ is good for me or the FZ40 odermaybe the FZ35/38 or bettter a nikon D500 or what. Thanks a lot