The Slowest One
I for one will never prefer a phone which pushes ads in notification or any other way on screen. I already face enough ads in my life on general basis, would rather keep phone clean with near stock UI. Another thing to keep in mind is android phones get sluggish over period of time, on top of that if the phone resources are being used to keep a flashy UI working instead of powering a basic smartphone functionality like launching a browser, takes 5 secs then the company doesn't really care about user experience. But if a person changes phone every 1-2yrs then phones like Oppo Vivo might suit them since they are a bit affordable and flashy.