You see how much dead space is under a short post? That's due to this forum using postbit legacy. PBL has the member info going down the left side of the post. Postbit has it running across the top of the post.
If they switched to PB then larger avatars would not increase the dead space under the post text. If you look at this thread at my place you'll see what I mean. > New logout girl
My avatar is 80x80. Cabbs is 105x110. My post has a large sig image where Cabbs doesn't. His post clearly shows the lack of dead space under the text of the post. The larger avatar doesn't make the member info header all that much larger. Resulting in a more compact post even with a larger avatar.
Bottom line is if the forum here decides to go with larger avatars IMHO it would be better to go with using the postbit style.
From my VB4 admin control panel:
Use Legacy (Vertical) Postbit Template
If you prefer the old-style postbit, using two vertical columns rather than the new horizontal layout, you can switch back to using that template with this switch.
Please note that if you enable this option and wish to customize the template, you should edit the 'postbit_legacy' template rather than the 'postbit'.
It's as simple as one click in the ACP.