Get a Cyclone instead. They're cheaper, feel great and stay in tune MUCH better. Put a better set of pickups in it and the Cyclone KILLS the Jagstang.

The thing with the Jagstang is that it wasn't what Cobain wanted - he had adimantly demanded a Tune-O-Matic type bridge because the Mustang vibrato is very unstable. Fender wouldn't go along with it, so Kurt barely ever played the prototype they sent him because he hated it.