>It's running Android - the closest equivalent product is the Samsung Galaxy S5

Kind of. It's running MIUI, which is like an iOS themed android (with some nice added extras, like the ability to block specific permissions on apps).

The closest equivalent product was the moto g. I was about to get one when they brought out the redmi (it's basically the same but cost $130).

>Speaking of ecosystems, does this thing have Google Play

Yep. All works fine for me.