I'm currently taking a break from the game until Cataclysm comes out. I was in a US Top 35 guild for the past few months, and still am, but I can't raid 7-12 every day of the week during progression nights while having school, a job, and still hanging out with friends.
Our problem in our guild is we do have "clickers" and some slow people. The clickers are very fast and long time members (smart members too). The slow people, we notice them and replace them. The thing is, we don't kick people out (lol yes we're not hardcore) and we raid about 5 nights for 25 mans putting in 3-4 hours. We're 9/12 heroic icc 25 with 11/12 heroic icc 10 man. Progression wise is good. Then you've got your smart members who are insanely good (god-like!) so really it depends on the leadership.
Clicking won't get your very far. I dare someone who clicks to do a fight which you can't do with yours eyes closed and the 30% buff carrying most of your raid. Can you say Heroic: Halion 25? GG @ 4 WAY DEATHBEAMS LOL

We don't use DKP or any of that stuff. One token and one epic per night. Usually it is a roll off or it will go to someone who can benefit from it the most (and is a core raider, of course).
I prefer a loot council for guilds that aren't full of skilled players, so the tool who keyboard turns, clicks, dies to stupid shit, and pulls piss poor damage doesn't gets an upgrade over you. Otherwise if you're in a guild who know what the fuck you're doing, I would prefer DKP since everyone is almost equally skilled.
Clear ToC25 earn gdkp points and triumph , go on to clear ToC10 for extra badges ( This was before welfare T9 ) and then login next week, rinse and repeat.
Try going for a Tribute to Insanity every week on 25 heroic (with appropriate gear level of course), then tell me if you actually experience end game content.