I am a touch screen enjoyer. At least in theory. I like having time to browse, look at pictures, easy access to customization options and most importantly no feeling of pressure. I am not spending a cashier's time and potentially blocking someone behind me (at least there is usually less of a line for the self-ordering).
However there are negatives for sure. My biggest annoyance is that these devices are often annoyingly slow and unresponsive. They just display a tiny bit of text and images, they should switch between screens at 60fps, not 2s per click. Also if I know what I want it is often faster to tell the cashier and let them enter the order (on their more expert-optimized and less laggy keypad).