Mr1der wrote:trigger, grip angle and nostalgia.
YES, yes and sort of. The nostalgia for me ties into the fact that there's a reason that the 1911 has been the standard measure for many for so long. Its a proven model.
Single action trigger pull is amazing in feel, especially if all you've ever shot is a DA/SA or a DAO - there is no comparisson.
Practicality is another reason the choosing something in the 1911 style. On one hand there's the knowledge that because its been around for so long almost anything modification that you might be curious about has already been done and consequently had all the issues worked out, and there's a HUGE group of users that might be able to help you or offer helpful suggestions along the way. In that way its a lot like the advantage of swapping a SR20 into a 240 instead of trying some esoteric VQ or 2JZ swap. The other big practicality point (and larger than the first, not sure why I listed them in this order) is that any gunsmith you find is going to have experience working on 1911's, its like the Ford Mustang of handguns and for this same reason ammo is rarely in short supply either.
Then there's the three integral safeties on it that make it impossible to fire (when handled by a trained user) unless they mean to. I had an old girlfriend freak out when she saw a cop carrying in Condition One (it was at a liquor store after some kids tried to pass a fake id), I just looked at it and then at him and gave a subtle, knowing nod. To her, she saw a gun with the hammer back that was ready to go off if someone sneezed. She asked me about it later and I explained how many things needed to happen for it to actually fire.
I don't think I'll be carrying a deep conceal piece in Condition One though, Israeli draw seems the way to go.