After being guildless for 3-4 weeks and taking 2 week break from WoW I returned to game and I applied to one guild. As a rogue it is hard to get to good guild on my realm, but actually I got invited.
First raid - thursday, I was in Mount Hyjal. First 3 bosses were killed day before, so only 2 bosses left. We killed Azgalor and we had 2 tries on Archimonde. We didn't kill Archimonde, but we are going to MH tomorrow to kill that guy.
Yesterday - friday, we went to Gruul's Lair, then Magtheridon's Lair and then to Zul'Aman. Half guild run, half pug, but no problem at all in killing everything except Zul'Jin. After watching Zul'Jin in action, we killed him on next try (Yes it was my first attempt at Zul'Jin and Hex Lord).
So in few days I achieved more than for few months in my other guild.
Oh yeah, I was first damage dealer on Azgalor and Mag. :)