I've been carrying the same Field Notes Shelterwood in my back pocket since April 15th. I posted my first stress tests on April 27th. My initial results showed wear and tear that was not much different from any other Field Notes carried in a back pocket. The results after almost a month aren't much different. Generally speaking I don't carry a Field Notes for longer than 20 days, so I'm now 5 days past my general carry length. Honestly, I can't say that the wear and tear, even after 25 days, would suggest that these notebooks are anything but sturdy. Yes, there are some chips and splinters at the spine, but when compared to other Field Notes the wear is decidely similar.
Though I have reached the limit of how long I carry a Field Notes, I'm going to carry the Shelterwood longer and see how it fairs. Gardening season is here, so be prepared for dirt and grime.
Here are some images of the spine, the cracks, chips, and wear on corners. You can also see the transfer of indigo from my jeans to the cover.