The first major downside is the material. A steel 1911 with a 5 inch barrel is going to be shockingly heavy. With polymer components now equalling or surpassing steel, it is a mystery why anyone would choose to carry a 1911. Almost every major gun manufacturer now produces handguns with polymer frames that are lighter and also recoil less than the 1911 because of improved designs.
The woefully inadequate round capacity of the 1911 is another problem. There is simply no reason to favor a handgun with a capacity of eight or nine rounds when double stack handguns in the same caliber can provide up to 14. Owning a 1911 for the collector's value is understandable, but do not fool yourself into believing that it is still on par with today's handguns.