Every review I have read says it works great, but is inconvenient because of the awkward way you need to hold the phone to allow it to scan your eyes. Something which is identical on the Note.
Every major review site who has talked about the Note 7 Iris scanner in relation to the Lumia one mentions how it is much better than the Lumia one. Apparently the Lumia required a VERY exact way to hold the phone while the Note 7 is more forgiving.
To me it's like fingerprint scanners on phone. Technically the Atrix had the first one of those, but it was a laptop scanner shoved it a phone that didn't work well. It took Apple's TouchID to have a decent implementation. The Note 7 is the first phone with a TouchID quality experience for its Iris scanning.
Anyway, you also said pushing the boundaries of what a smartphone can do. A novel way to unlock a phone doesn't push any boundaries. It is a nearly useless gimmick IMO.
I think the Secure Folder tied to the iris scanner is a big deal. We can now lock up our most secret information in the same way that a 1990's movie villain would- behind an eye scanner. Pretty cool.
I mean sure the iris scanner isn't like the first time we got a camera flash on a phone, but it's a bigger deal than many gimmick smartphone features that we get because it works well. Plus Samsung is already far ahead of anyone else on innovation- VR, a workable stylus, the best screens, etc.- and the Iris scanner is just part of the package.
The last innovation Apple rolled out was 3D Touch, which was such a big deal it didn't come in the newest iPhone release AND it basically won't get full use until iOS 10. Relative to Apple the Samsung devices have been innovation factories.
We won't see something truly groundbreaking in the smartphone space until foldable screens (which again Samsung and LG are on the forefront) become a "thing." Even the iPhone 2017 that has everyone excited just sounds like they are finally catching up to what Samsung ships today in form factor.