With 3D Touch, Apple wanted to add a new layer of interaction to the iPhone. Through the use of pressure sensors embedded into the display, the phone can detect and respond to hard presses into the screen, enabling 'peek' and 'pop'.
My experience with 3D Touch as been similar. When I bought the iPhone 6S, I was stoked about this technology. Never before had I used a pressure sensitive display in such a form factor. I went around exploring the possibilities of 3D Touch within apps, used Live wallpapers on the lock screen just so that I could press into them. I skimmed through emails, switched apps in multitasking and pressed into random app icons just to see what's hidden under them using 3D Touch.
Today, after 6 months of using this technology, 3D Touch has become so natural that I do not care about it anymore. I still use 3D Touch, mainly for multitasking and sometimes for reading through large number of unread emails. Yes, I still click live photos but I toggle it on and off as per my requirement. None of this utilises the true potential of 3D Touch.
Is 3D Touch a big deal anymore? Absolutely no. Either people have gotten so used to it that it has lost its charm, or people just aren't happy with its functionality and aren't using it.
With WWDC a month away, I'm looking forward to see what's in store for 3D Touch in iOS 10. The expectations aren't very high, but I'd love to see a lot more functionality through this "new from of interaction"