Fortis are
terrible, at least mine was and I am the friend Sicknote mentions below.
The first problem I had was the GMT hand would snag on the second hand, which made the watch stop. After that had been repaired I had about two weeks without problem and then started to note that the GMT hand would lose about two hours every day (as a GA pilot learning to fly instrument, I do actually use the GMT hand to get the time when communicating with ATC so that was just plain unsafe). It is now sat on my desk with a repaired GMT hand but now the hour hand has become disconnected and just swings around on its own. I may get it repaired again but I'm in no hurry. It is a shame because the Fortis GMT Chronometer Automatic, the model I have, is a damn useful pilot's watch, it looks great and has all the functionality we could ever want.
In disgust I bought a Breitling Airwolf, which works just grand. It looks cool and is a lot lighter than the B1 it replaced. It also has night vision compliant LCD display lights, which will come in very handy when flying a Cessna 172XP
I like the slide rule bezel although must confess to forgetting how to use my E6B after I got PPL - hat off to Slopey on that one.