The new Microsoft one is pretty good, but it is basically a very attractive game rather than a learning aid. Maybe I just have a rubbish joystick, but the lack of any feedback through fingers and bum takes away most to the inputs I (VFR pilot) use day to day.
Another issue is that the scenery is so good you really don't want to confine yourself within the cockpit where you can hardly see anything of the outside world. Better to tour the globe in external view. I have spent a lot of time around Hawaii, and also flying the Thames through Central London. Top tip here, you can't emulate Flt Lt Alan Pollock
For students, I envy them the ability to practice their cross country flights, what I wouldn't have given for this all those years back.
Rob P