I tweaked it a little, since only my super-moderators and administrators can ban users, not regular moderators. I also added another if condition so that it'll only show "ban" if they're not banned, and if they are it'll only show "lift ban".
Code:
<!-- QUICK BAN -->
<if condition="$post[usergroupid]!=6 AND $bbuserinfo[usergroupid]==6 OR $bbuserinfo[usergroupid]==5">
<if condition="$post[usergroupid]==8 OR $post[usergroupid]==9 OR $post[usergroupid]==108">
<tr><td class="vbmenu_option"><span onmouseover="this.style.cursor='hand';" onClick="window.open('modcp/banning.php?do=liftban&userid=$post[userid]','liftban','width=800,height=375,scrollbars=yes')"><b>Lift Ban on $post[username]</b></span></td></tr>
<else />
<tr><td class="vbmenu_option"><span onmouseover="this.style.cursor='hand';" onClick="window.open('modcp/banning.php?do=banuser&userid=$post[userid]','ban','width=800,height=375,scrollbars=yes')"><b>Ban or Suspend $post[username]</b></span></td></tr>
</if>
</if>
<!-- /QUICK BAN -->
It's set so it won't show up on admin posts at all, but only admins and smods will see it under the dropdown. Usergroups 8, 9 and 108 are my banned, temp-banned and sig-revoked usergroups, respectively.
Other than those few minor things, I'm glad you got this up for 3.5. Thanks.