Well after reading all the comments to this point, I have to say in fairness to Samsung, they do tend to refine their new features over succeeding generations of devices. Around the time Apple gets around to implementing this the optimal way so that it fits in with their "it just works" credo, the iris scanner will also operate better on the Samsung of that time, too.
I am planning to get the Note7 and so I have spent some time getting a feel for the Android users community and I think what we see is that Samsung knows its target buyers like to experiment and fiddle around with the devices to a certain extent. They're more likely to at least tolerate a cutting edge new feature that really isn't ready for prime time than Apple buyers would.
Android users seem more likely to just shrug and say "Oh cool, let me try this...ah crap, this sucks, I am going to ignore it" whereas Apple users are more likely to say "This sucks, what the hell is this doing on my iPhone, somebody fire Tim Cook now!" I know that's a broad generalization, but that's how I see discussions playing out when I look at old archived Android/Samsung discussions and compare them to the Apple ones that are more familiar to me.
So Samsung is not actually slapdash and Apple is not really glacially slow. What both companies are is much more savvy about their user base than we've been giving them credit for in this thread. People look to Apple for different selling points than Samsung customers evaluate Samsung products by.
However I do see some overlap and I do see some customers getting a bit restless with Samsung's persistence in trying new things. I don't know if these users are converts from iOS or if they are just tired of being perennial beta testers for new somewhat half-baked features, but I do see some of the some concerns and complaints voiced here posted on their forums as well.
I would imagine that Samsung will hold to the Android community's expectation of customizable options and will allow this scanner to be disabled and allow the fingerprint scanner or passcode to be used in its place. If not, I will return it.