Their censorship got out of control such that even the serious, non-bullshit posters couldn't take it anymore. Mayhem's failure opened the door for all the sites that emerged later. GetBig is still the grandaddy of them all, though.
They had a ton of good people for quite awhile. BigJimbo was probably my favorite- but whatever happened to him nobody knows. He always scoffed at others when they'd make the infamous last post "My last post, I'm outta here because this board blows" or whatever. He said he would kindly just bow out, and that's exactly what he did.
Then you had all the Pros. Seemed as if GetBig had a few guys here, like Prince under the handle "The Thing" and later "CrankYanker." Titus, Kamali and a few others came and went. But MuscleMayhem really seemed to be the place where the Pros flocked to, I think probably because Chad, and maybe because they were allowed to moderate but unsure. Prince was a good poster, when he wasn't off his rocker. Later on though, he was more off than on with the pious attitude.
I was going out of town quite a bit, and it seemed that one day Mayhem was up, the next it was deader than the thought process of MattT.
They had guys like Tumblin'Dice, and other controversial characters there. People called for them to be banned or tagged a "Blithering Idiot," and it seemed as soon as the popular vote was heeded, the board lost it's luster.