I visited during Calgary's burger week. I only found out about this event on the last day and after trying Burger 320, I wished I had known sooner and had visited at least a couple of times that week :)
I had a sprouts burger with mozzarella cheese, rosemary french fries and a tiramisu gelato for dessert. All of it was simply de.li.cious! The patty: fresh, rich, made from scratch! The bun: big, soft kaiser bun. The fries: perfect amount of herbs to give it a different flavour.
The only downside is that the place is tiny. I am totally ok with buying a burger to go, but if busy you may have to line up outside in the cold. That takes away a lot of its charm.