Force Touch is an impressive piece of technology. It currently equips the Apple Watch and the new Macbooks. You press firmly on the screen and the haptic engine will register a "deep" press.
On the Watch, I found that the feedback was not properly mapped to the press (it's a tap on your wrist, not on your finger). I didn't use the Watch a lot, but I've also found that it was sometime hard to trigger.
On the new Macbooks' trackpad, the feeling is fantastic. You can push multiple times and sense the force you apply like it's real. You may not even understand that it's not a true physical button.
But… Force Touch is not discoverable.
There is no visual clue that Force Touch is available — either on the screen or on a specific control. It's like the menu button of the old Android versions: you tap somewhere (the menu button on Android, firmly with Force Touch) and something may happen. Or not. It's confusing and it's one more hidden gesture with no affordance. It's no better than a long press if its sole purpose is to be another context menu.
Indeed, on the Apple Watch, Force Touch's goal is to show a secret menu with additional actions. I understand the purpose — the screen is small and you can't fit everything on the screen. But this exact same behavior on a bigger display will have the same problem that Android had with its menu button. It's even worse than a hamburger menu, because the icon won't be there to tell you that an additional layer is present.
On OS X, I found that the usage of Force Touch is better: it's not a way to show secondary actions, but just a "deeper version" of an action. In QuickTime, for example, you press firmly on the forward button and the video will fast forward faster for each level you reach. It's still hard to know when it's available and might result in nothing, but at least, it's consistant with its source.