Here is a Greasemonkey/Tampermonkey script that should work. It is untested and unhosted at the moment. :
// ==UserScript==
// @name Stack Exchange, Comment cleanup
// @description See stackapps.com/questions/7202/
// @match *://*.askubuntu.com/questions/*
// @match *://*.mathoverflow.net/questions/*
// @match *://*.serverfault.com/questions/*
// @match *://*.stackapps.com/questions/*
// @match *://*.stackexchange.com/questions/*
// @match *://*.stackoverflow.com/questions/*
// @match *://*.superuser.com/questions/*
// @exclude *://api.stackexchange.com/*
// @exclude *://data.stackexchange.com/*
// @exclude *://blog.stackexchange.com/*
// @exclude *://blog.stackoverflow.com/*
// @exclude *://chat.stackexchange.com/*
// @exclude *://chat.stackoverflow.com/*
// @exclude *://elections.stackexchange.com/*
// @exclude *://openid.stackexchange.com/*
// @exclude *://stackexchange.com/*
// @exclude *://*/review
// @require http://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js
// @require https://gist.github.com/raw/2625891/waitForKeyElements.js
// @grant GM_addStyle
// @version 0.5
// @history 0.5 Initial release, untested
// ==/UserScript==
waitForKeyElements ("a.comment-link", useShortLinkFormat);
function useShortLinkFormat (jNode) {
var oldHref = jNode.attr ("href");
var commentNum = oldHref.match (/.+?comment(\d+).+/);
if (commentNum && commentNum.length > 1) {
var commentNum = commentNum[1];
jNode.attr ("href", '/posts/comments/' + commentNum)
jNode.append ('<small> sl</small>')
}
}