Ive only got one sim in mine, but if you have 2 sims in the phone they can both make calls and text. would be useful for say a work/home numbers. As for the system its very similar to a moto phone, just stripped back in certain areas. The moto display only as peek display, and actions limited to double chop for torch and twist for camara. Phone already on andriod 9, i still have a moto g5splus which to be honest i prefer. But i will be suprised if it gets any more updates, if you buy a one beware the sim slot is flimsy and the phone is very slippery without a case.