They are great for practising the dials for IFR flying, not much use as an actual 'this is what it's like to fly an aeroplane' type thing as I invariably find them much more difficult to fly than a real a/c.
We have a three screen set up at our club with the yoke, pedals, throttle quadrant etc. I was trying to do an ILS into Doncaster on it when a prospective stude was shown round. I had to explain to him that the sim is 20 times harder to fly than the real thing as I lurched around on it. Most embarrassing.