I have a Nook STR but it has only whetted my appetite for Kindle Touch. The nook is too stripped down, and there have not been any meaningful updates to address things like text selection issues, lack of multi-level TOC, and the strange behavior of the Text Options panel. My impression is that they won't get around to it, most of the same problems exist on Nook Color and haven't been fixed.
Lack of SD is not an issue for me. Nook won't even let me delete my own content without hooking up to a computer. Amazon is hooking up 5Gb of free cloud storage for 'Personal documents' which will sync and backup bookmarks. Kindles can also download content from the web (including dropbox, calibre content server), and you can push content to it via email. That's much more functional for me than Nook's very restrictive use of wifi, and more convenient also.