iPhone 6 Plus Optical Image Stabilization: Does it really work?

I've been playing a lot with the camera on my 6+. It takes amazing pictures and video. Also, Camera+ just updated their app and it's amazing the amount of control they give you in that app. You can now control the shutter speed, ISO, focus and exposure points...really turns the camera into a powerful tool. But I digress...

So the 6+ comes with optical image stabilization, but to be honest it's hard for me to tell if it's really doing anything. I have a Canon DSLR with a couple of lenses that have OIS and when it's active, you can tell a huge difference in the preview before taking a shot. The camera shake is almost gone when looking through the viewfinder, turn it off and the view out of the camera becomes way shakier.

With the 6+, I just don't really see that much of an elimination of camera shake. I have to hold it pretty steady to keep the image stable before a shot. And when I compare the image preview to my iPhone 5 they both seem to 'shake' about the same. Is the OIS really working? I would assume it is, maybe just not as noticeable as my other experiences with it. Maybe it's a lot more of a minor stabilization than my DSLR camera lenses? Just wanted to throw that out and see what other people think of this feature.