At least on the reliability question, personal experience with both tells me that stock 4506s will generally perform hitch- or hiccup-free, out-of-the-box, better than stock (i.e., noncustom) 1911s.
Having said that, though, there are certainly 1911s I've handled that have run jam-free from the very first shot. But I've handled many (mine and those of others) that didn't - not without having to see a 'smith at some point.
However, with the spread of CNC-machining within the gun-making industry, probably the more recently made 1911s will perform better out-of-the-box than their predecessors of 10-15 years ago.