Kind of off topic, sorryyy. <3
I don't have much I can contribute here because I'm actually pretty new to GMing, but I have to agree with uncelebrated.
On my server we're allowed to have legits. At first I was really pumped because it was really tough for me to choose being a GM over playing a game I've loved for, like, 8 years. Once I actually became a GM, though, I think I've logged on to my legit maybe 4 times (at least 2 just to test something that I couldn't test using my GM character). I just don't have the time! I work full time in real life, and I'm also the art/sprite GM. So essentially all of my time outside of work breaks down to probably 70% in game GMing, 20% art for the server, and 10% everythingelse. xD
I guess it comes down to what kind of GM you are. I'm a head GM with a special job as well, so basically I police, support, event, and sit around looking pretty and showing how nice the staff is on top of my spriting/art job. Someone like me can't possibly have time for a legit. On the other hand, if you split the GM's up and have one for each of these roles, they could have enough time for a legit, I suppose.
It's a tough subject for me because even in my short time being a GM, I have seen GM's letting their job get affected by playing on their legit character. Basically just sitting around dual clienting on @hide or just not being online at all. It makes my job even harder, honstly. xD;