I am sure you all noticed that since the last patch, instanced zones have been very unstable. From personal experience, moogle and garuda were almost non-playable at times, due to people DCing, crashing, or in some cases the entire PT DCing.
All instances are messed. Hamlet / Moogle / Garuda etc. And it seems to affect Balmung more than any other server.

I am posting this because it seems there are a lot of people still not aware of how serious this problem -can- be. My whole PT DC'd (9/4/12) while fighting Garuda. All 8 of us are still unable to log back into the game since, and there is very little being said by SE or anyone else that could help us. Seems like they don't know how to fix the problem, as GMs and tech support are clueless. GMs flat out refuse to help.
At best, you'll just get really annoying DCs/crashes during instances. Land the killing blow on Garuda and DC, or some other BS. At worse, you'll join us and get locked out of the game. There are threads of people having problems connecting to their character for weeks without resolve.

So, play at your own risk for a game you are paying money to play.
Or, play it safe and don't do instances. Pay for a service you can't use.

http://forum.square-enix.com/ffxiv/threads/53498-BALMUNG-SERVER-GARUDA-INSTANCE

http://forum.square-enix.com/ffxiv/forums/135-Technical-Support