I don't get those reviews and honestly doubt their authenticity. While it is possible that some people have different preferences, this is just extreme.
The doners or shawarmas or whatever they like to call them are not authentic and have nothing to do with the real thing. They are messy and very frustrating to eat, and the portions of the different ingredients are all off. The place itself is dirty and many of the products being sold are expired or not sealed correctly.
On the bright side the staff is nice, but that's easy to come by. Anyway I would advise you to go elsewhere. If you do enjoy their sandwiches then great, but please know that they are not authentic.