A hifi isn't a car, anymore than a sandwich is the river Thames.

I too think that dealer dems are pointless.  The only way to test anything is to do so in your own time in an environment you are familiar with. 

I think it is also very important to decide what you are interested in.  Stepping out your front door with the inclination to listen to every turntable on earth until you find the best one would be disastrous.