I'm gonna have to disagree with Willie Sutton on this one. I've seen very few 1911s in classes over the past few years. Gunsite 250 may be the most awesome pistol class ever, but like it or not, a quick review of what people -- professionals, military, citizens -- are taking to gun school these days is going to unearth mostly double-stack 9s.
And if you can't effectively conceal a common double-stack 9mm (i.e., Glock 19, SIG P-228/229, SA XD/XDM, M&P), you just don't get it ... As for training what you carry, hell, a lot of the people I know proclaim their love for big guns, but in reality, pack little bitty single-stack 9s and .380s -- except for the true professionals that I know (and work with) who DO carry full-size guns, but usually NOT 1911s. (Maybe we're just different up here -- all the rain, perhaps?)
1911s are my first love, but I can't ignore what I've witnessed over the last several years.