Which do you shoot better? You may want to find a Range that offers rentals and see, or borrow one from a friend. You may find that the grip of the Glock is too short, or too fat... Definately, not everyone fit's the same.
In my case, I can shoot the Ultra much better than a Glock 27, although I have gotten better more recently with the "Safe Action" style triggers. Still, it really depends on the individual.
Personally, I don't think I would carry a short catridge style in a 1911. For most, the 40, or the 9x19 works fine, but knowing that the action of a 1911 works much more reliably with a longer cartridge length like the 45, 10mm, or 38 Super, I would gravitate that direction, YMMV.
When deciding on a particular gun for CCW, you should also factor in whether or not you are prepared to adjust your dress to aid in concealing your choice, and how you plan to carry it.
I find the Glock grips too thick for me, and especially, when IWB is the preferred mode, although some rig's do work better than others. Again, it will all come down to personal preferrence.
Good Luck.
