It's not the missing headphone jack that bothers me on the U11. Its the way HTC implemented the earphone sound. On the "10", you can adjust 5 frequency ranges for each ear. If done "correctly" and paired with decent earphones you get fantastic sound. On the U11, there are no adjustments. They removed the app. Instead, you have to use the included earphones. They supposedly sense the shape of your ear canals and adjust the sound accordingly. If you use any other earphones, even with the included dongle, you cannot adjust the sound. That is the killer. If your hearing isn't what HTC considers perfect, you're out of luck. Its crazy. The U11 ignores the entire earphone industry and anyone that doesn't have "perfect" hearing in both ears. (like myself) I can't imagine the cost of adding some form of radar to the phone and designing earphones that can send and receive it. Then, after all that engineering, they skimp on the sound reproduction.
As far as your feelings about HTC phones fulfilling your needs, I have the same concern. I've been an HTC fan for years. The "10" has been the closest to my perfect phone. Now, as you said, HTC has gone off in a completly different direction and lost me. Unless the U12 render has some basis in fact, I too will be looking somewhere else. If you should find something promising, please post it. Good luck.