I've been keyed for Karazhan for months, but I was never able to attend. Largely because it's somewhat rare for me to have 2 nights off in a row, and absolutely impossible for me to have the 2 nights that my guild ran it on off.
Recently, a guildie began organizing a Karazhan guild pug to gear up alts and people that aren't part of the core raiding set. This would only be a one night thing, as it happened on Monday before the reset, and would be an attempt to clear as much as possible.
I was brought in as offtank / dps, due to my dps set severely outclassing my tank set. We cleared Attumen, Moroes, Maiden, Curator, Shade of Aren, Opera, and Chess. We almost killed Prince, but half the group had to go so we called it. We did not kill Illhoof, Netherspite, or Nightbane.
We wiped a few times, but cleared a lot in a fairly quick amount of time. Even though I offtanked quite a few pulls and bosses, I still ended up #1 on the dps meter by a pretty large amount. I can't wait to go again, and with the new tank gear I got from the run (bracers and boots), I might just main tank it.