Not a 1911 guy myself, but the Platypus I handled recently was just as you mentioned. Very nice action and eliminates some of the consumable costs of high $$ 2011 mags. I didn't get to shoot it, so can't speak to how it runs, but as I understand based on your posts, it runs well.
If you are buying a 2011 and the costs of magazines gives you pause that’s your hint to not buy a 2011 , nice all steel magazines aren’t cheap, a 2011 mag is as expensive as an MP5 magazine