I've read several avatar-size threads now and the answer to changing their size is always, there is no way to do that without code and template edits. Well, I'm game - how do I do that with code and template edits? I'd like the avatars to be a full 124x124 and I'll just eliminate the padding.
You will need to fine tune paddings for the poster information block. You will need to re-upload your avatar so the new "m" size can be saved. Also, the three default avatars should have their medium size changed to 124px too.