One suggestion I would have for the mobile version is to have a "sticky" page navigator in the Head-Fi bar that scrolls along the webpage as you browse through a thread, or at least have one at the top of the thread webpage. It is a hassle to scroll down to the last post of a thread, especially if there are long posts, to access the "next/previous/first/last" page navigator.
Also, I'm not sure if it's just with the iDevices (I'm using iOS 6.0.1), but I'm not a fan of the "basic editor" as opposed to a desktop's "rich text" editor. I can live with it, but it's really inconvenient to scroll through the HTML code while editing/posting a reply as I've made a few posting mistakes with it.
Edited by miceblue - 2/3/13 at 7:45pm