In terms of working best with the Model 3, the OP would have better odds with an iPhone. All the surveys so far have shown androids have far more issues working reliably as a key.iPhones are not the only answer..
Androids, i.e. Samsung work just as well, if not better. You have a ton of choices. Just stick to newer models.
My M3 hasn't arrived yet.. so nope, net yet.
The people above this post could you please share how your phone keys are working 100% of the time correctly. How do you have your phones set up for connectivity via app, phone, and car.