i was lucky enough to get an invite for being tw (i think i was the last one even)
anyhow i couldn't be happier with the folks at serenity now...
now i can't speak for the officers, but from my entire time in wow, it's about two things:
1) personal suitability
2) common goals and objectives
If you don't get along, you never will. Immaturity is rampant in the game and you can either choose to let it bug you or let down your guard and have a laugh. My favorite aspect of SN has been the countless laughs. It was awesome to try to fit in with a bunch of fun strangers and i think i'm still trying to break the ice with a few people but i've always been welcomed with open arms. I laugh so hard night after night on our vent... i can't imagine having more fun.
I also think it's important to share goals. Like any business, you have to staff your team properly, along with personal suitability, you also need people to walk the line with you. You can't have a group that can't raid, doesn't want to raid etc, you need to be on the same page. Managing 40 people with regards to objectivity isn't easy, and you need a solid core of people that will approach the game in a relatively similar fashion. Otherwise you'll crash and burn.
As you app to guilds, you should be evaluating them too. You can't just keep chasing the successful guilds and expecting it to work out. You have to find a guild you have fun with.