After being on my 'to try' list for what felt like ages, a few weeks ago I finally went to try 4food with one of my friends in work as it's just a few blocks from us.
On the day we went they had some sort of promotion going on and were doing email opt-in, promoting their loyalty card... they have the social component of their business. Working for a company in the digital marketing space, we were both pretty impressed.
They offer a pressed rice bun, and also note the gluten 'allergy' when you are ordering. Gluten containing items are also clearly noted on their menu. My first one I had with swiss cheese, avocado and a turkey burger. I didn't get a scoop, not knowing the burger patty is ring shaped for said scoop... however it was really good.
The actual bun is literally sticky rice pressed together. It holds up nicely, although when I did go back and had a scoop I found it was very slippy/messy to eat. I am a big fan though and while I won't go all the time, I will certainly be back with some sort of frequency.