I really enjoyed the design when I came in. And that's probably all that I enjoyed. I waited around 20-25 minutes for the meal (also 10 minutes for the receipt) and when the food arrived I was a little disappointed. The portion was kind of small.
Maybe I'm too used to the other cafes and restaurants in the area, but for 7 euros I expect more. My colleges ordered burgers, and that must have been the smallest burgers I've seen in my life.

I don't think I'm coming back to Nat.

I was really impressed with Nat. when I first walked through the door. Spacious, very white - airy, it's a lovely design. They've clearly spent a few quid on it. Although I believe run by the same people as Vapiano, thankfully you don't get the stress of queuing to watch your food being cooked here. The service is quite good - the food came in reasonable time, and was very tasty. I felt, perhaps being a glutton, that the portions were too small. Actually - perhaps not because Stephan ended up ordering two main courses still being hungry after one.
If this were London and you were paying €10 for a main, you'd think it was fair enough. However, compared to the other lunch choices around here (Luna in particular), Nat isn't great value. You do seem to be able to get a table though, so 4 stars for that all important factor!