I believe EEs don't meet breed standards as APA Ameraucanas. The EEs are bred like a landrace where color of egg or color of feathers or color of legs and absence of a muff don't matter. However in the APA Ameraucana there are strict guidelines about leg color, accepted APA feather colors, blue eggs only (no pink, olive, brown, or white), have muffs/beards, certain kind of comb, etc. With EEs the outcome of chicks is Heinz 57 mixes whereas there is a lot of careful breeding for the actual Ameraucanas. Getting a guaranteed blue egg layer is why I chose to order an actual APA Ameraucana rather than take my chances about what color an EE would lay.
Otherwise my friend and I find no difference between them as far as personality, gentleness, and prolific egg layers and it's always a fun mystery what color egg an EE will lay. One BYCer had an almost pure white EE with beard/muff and was surprised when it layed white eggs when she was hoping at least for a bluish-green or even pink. It's always like a box of chocolates - never know what color egg you'll get with an EE. But very definitely it is a very sweet unusual chicken.