But, Evernote's Page Camera feature that was added to the iOS app does seem to work just fine with other paper (I tested Field Notes w/ graph paper). It's just 'optimized' for the paper in these notebooks, whatever that means.
If it does make a significant usability difference, that would be pretty cool and I'd love to get some insight into why dotted lines would be simpler for image processing software to work with than straight lines, but... For now, I'm gonna keep on trying to bury myself with post-it notes...
Unless scale is important but I can't see how that could be.
It most likely helped a good amount in bringing this feature to market as quickly as possible, and it'll be interesting what they do with the dotted pattern concept in the future (I see it either fading into an edge case of the software that becomes a technical debt for the remainder of its lifetime as the algorithms for handling the base case of any arbitrary notebook paper improve, or evolving into the base of an Evernote certification process for notebooks).
Personally, for me this feature is the tipping point between "yeah, Evernote seems kinda cool" and "I'm actually considering using Evernote (assuming the feature finds its way to Android)". The only improvement I would make that would really seal the deal would be the ability to fax all my notes to Evernote instead (seems like much less a pain in the ass for digitising volumes of notes than meticulously photographing each page), though I suppose that as long as they support manual uploading of images through their desktop site this would be fairly trivial to script myself.
$25/notepad is way of the charts for the types of notes and sketches that I actually need a notepad for.
It gets harder if the notebook doesn't lie flat, though.