I did, went from an iPad 4 32GB 3g to a 16G 3g iPad Mini with retina. No regrets. Also went from a 2012 Macbook Pro 13" to a high spec'd Mac Book Air 11".
Moving to a lighter, more mobile hardware so I can work more efficiently while commuting, traveling and tighter spaces, The Mini helps me to accomplish this. I do not plan to upgrade my iPhone size if they decide to make a bigger screen.
Minimal gear, high productivity.
iPhone is even more mobile than the ipad mini. Does it not suit your needs?