I've had my One for about three weeks now and have to say it's the best phone I've ever had by a fair margin. I rooted it and installed Calkulin's v1.1 within five minutes of rooting it and have basically only used this ROM and Slim since getting the phone. Both are great but each also has small issues to deal with.
My issue with this ROM is a puzzler to me. For some reason it seems to think my sim is not legitimate and on each and every boot it sends a text message to the other phone on my account (i.e., my wife!) with my phone info, location coordinates, time and % battery life. Ditto my Cerberus app sends an email to me saying "unauthorized SIM inserted", along with all the same information as the text.
This has happened on every boot on all versions of this ROM (1.1, 1.2, 1.3). I don't get this on any other ROM (Slim and tested Mahdi today), and I'm setting them all up with the same apps and as similar config as possible. Pretty sure it's nothing to do with the kernel because it does the same thing on the ROM's stock kernel and AK (on this ROM only).
Other than the fact that the phone spits these messages out, everything works fine and I have voice and data exactly as I would expect and there are no errors or log messages that I can find. Oh yeah, standard sim I got from the T-Mobile store...