Well I've GMed before, and have done it for mostly short campaigns. Those seem to work the best for me. Long winded ones tend to get dry as I don't have a whole lot of substance. Also, I'm not very bendable when it comes to GMing, nor am I fit to be a GM of a bunch of random people. I'm bad in the fact that if I think you're going to do something (or even come up with three different scenarios in my head that you might do), and you do something absolutely random that I couldn't have even conceived of, I don't do so well adjusting to that. It's one of the things that caused me to have a falling out with my last group. They were working for a corporation that gave them jobs to do, and eventually they decided they were going to form a rebellion. Why? Well, the last job they did apparently left them all with a bad taste in their mouths. Considering only one character was good (NG), I didn't see the problem with it. To quote from Heroes, they were orignally "comfortable with morally gray." They were either going to defeat the corporation and take it over, or die trying. I had no prior knowledge of this (and why would I?), so when it happened, I was so shocked that I kind of did what I could to not kill them off and close the campaign. I eventually argued with, lets call him, the "Head GM" (as he's considered the leader of the group by most and was someone I once respected) to the point I had to walk out before breaking him in half. I haven't looked back since, and needless to say I was quickly replaced. I've GMed one-shots at gaming conventions, however, and those seem to have gone well. To the point I was even asked to come back many times, and games I couldn't make it to made people sad. So I know I'm doing something right. But those people know what they're getting into, and want to get involved with those kinds of storylines, whereas this group just wants D&D combat whenever they can get it (save one player who has no problems with us being lvl 2 for the rest of the campaign if the story is there).