I just re-downloaded Vice City on my iPhone yesterday. It runs well, but the on-screen controls are, well, on-screen controls. That limits how much I actually want to play it.
I just tried an 8bitdo controller I had lying around. It does work, but the controls seem all wrong and need to be remapped. I may do that.
I never carry a controller with me. I'd love to just be able to pick up and play in a waiting room or something without needing to plan for it or having an awkward setup. The MCON looked promising, but still probably bigger than what I'd want to carry around.