I am developing an SMS based system, and I was asked if the cell phone model has a significant effect on the arrival time of the SMS. Although, I'm a bit sure it doesn't because of my testing.
I have tested my system on different phone models, from old phones to smart phones, and the SMS arrives on time almost instantly. Although, it would still be nice to have some real proof if it affects, or not, the arrival time.
I googled this, but it just resulted in how cell phone and SMS work.