I shared a create-your-own pizza with my sister at this Pi Co location last night. The service was lightning-fast which, together with the smaller location, mean it's best set up for take-out. We decided to eat in as we weren't anywhere near home and had to reserve our seats with our bags while we ordered (yes, we were THOSE people) and were rushed out by other customers circling the table as soon as we'd taken the last bite.
Despite the tight squeeze and rushed meal, the experience was great. The pizza's thin crust helps stave off the guilt so you can totally eat a whole pizza without feeling bad. There's a good selection of toppings.
I think the process would be smoother if the pizzas went to a 'finishing' station before paying, where you can choose to put your arugula or balsamic vinegar etc. on after cooking.