Wow - I'm surprised at how a curved traycase spine and a different material make it so much more appealing! The sum of the small changes like would tip the scales for me with some of the lettereds that I just want to like but can't because the production values just aren't there (see: the lettered Imperial Radch trilogy, which I loved, but which just isn't 5x better than it's S/L equivalent).

Part of it also just seems like a missed opportunity. Once one small press has done an S/L edition of a book, no one else is going to get the rights for quite awhile.

Full disclosure: I did pre-order the lettered Provenance because I wanted to see it for myself and because it'll be easy to flip if it's disappointing.