I've been to Vapiano about 7-8 times. The food is decent, if you get the right line cook to prepare it. It seems like they have high chef turnover. The drinks are also decent, and the bartenders have always been courteous and attentive.
I decided that I won't be returning after my visit today. Brought my whole family and when we went to pay our bill, the credit card machine was "down". The cashier, in a very rude manner, informed us we would have to pay cash. None of us had cash. One member of our party ventured a few blocks to the atm, and while he was gone, I noticed another patron signing a credit card receipt. I asked the hostess if the machine was working again, and she simply said "yes".
So she couldn't mention it was working again? And was the rude attitude necessary? That's enough to turn me off from the business. Too many other good places to eat in Charlotte. We spent over $100 there today and were treated like crap. We complained to the manager on duty, who was also quite rude, and left.
Good luck.