This might be more suited to a community poll (mods feel free to add one to this thread if you'd like and if this is possible), but personally I feel like it would be a lot more convenient if the forum automatically returned you to the thread you were reading after posting in that thread.
I know you can accomplish this by clicking "Attachments and other options" and then checking "Return to this topic" but a lot of times I forget.
If users are split on this kind of feature, a user preference to change the default setting for that option when posting (checked or unchecked) would suffice just as well.
Not a big deal, and I haven't dug into the user prefs in detail yet, so if this option is already there please let me know.