I use a Samsung Galaxy S2 phone. It has a comfortable 4.27 inch AMOLED screen, quite a bit bigger than the screen of the iphone.
I'm thinking of upgrading to the new Galaxy Note which has a 5,3" screen.
In my experience the much larger tablets take some getting used to. You need to move your fingers over longer distances and at least initially I found I was much more vulnerable to enemy fire on the Galaxy tab than on the sleek and elegant S2 that is so easy to handle that it almost feels like a part of the body.
The uneven, slightly step-wise movements don't seem to depend on what phone you use, but probably have more to do with the update frequency of the mobile networks.
I think that whatever phone you use, you will never have really smooth movements, and aiming at a distance will never be really easy.
If I use an hdmi cable to connect one of my phones to a TV set, I get pixel sharp images, and it's much easier to see planes at a distance, but the uneven movements also become much more noticeable. What is ok on a phone, becomes unpleasant to the degree it almost gives you motion sickness when transferred to a large screen.