Thanks for asking. I totally agree about the quote and url functions. That might make me use the mobile view.
There's no extra space on the mobile screen for extras, I'd rather keep all visual extras off. I use the full site for the extras and the beta view opens up with just the corner and the hugelkultur article. Too visually cluttered, I have switched back to the normal view.
I'd like to have navigation links at the top and bottom of the screen, it is a bummer to have to scroll all the way up from the bottom of a long thread or down to the way bottom if I find myself on the wrong page.
Please remember there is no hover function on a mobile device.
Also, when you click the link from notification emails on your phone, it doesn't take you to the exact post like it does on the regular computer, only the top of the thread. It'd be nice for that to somehow work.
Besides what has already been mentioned by Cass and Matu, (especially the nav links at top and bottom, and the ability to url and quote,) a way to switch back to mobile view from the non-mobile view without having to close and reopen my browser would be cool.