Yes, I have tried other burger chains such at Byron's etc but I still think GBK is just better. My personal favorite is the avocado and bacon burger which is always perfectly cooked and just amazing without being greasy and bleughh.
I think its a great place to go with friends because each person can go up and pay individually and so you don't have the awkward splinting of the bill. Side note, we were doing this in Berlin and it was just so complicated and I think a few waitresses were pleased to see the back of us!
Just look at that burgery goodness!
Another great thing about GBK is the app. If you are able to download it, it is SO worth getting. It's free and each time you go you receive a reward. For example for just downloading the app you get a free sauce! Who doesn't love a bit of free food?! For those with smaller appetites they have a lunch time deal where the burgers start at £5.95, what a bargain!
I really recommend a visit, my local never disappoints.
Have you visited a GBK before?