Calder S.
Yelp
This was my first time trying the Halal Guys and it was pretty good. I ordered ahead using their mobile app, and got a free drink and side as a first time customer. The mobile app is pretty good -- it is organized, straightforward, and performs well. There are a lot of customization options, but most of them cost money. I missed out on customizing my sandwich with the free options (chopped green peppers or chopped onions) since they were buried among the paid options. Sides include things like fries, hummus, and falafel. If you want to max out your free side value, get the six piece falafel. For drinks, they have a basic soda fountain with Coke, Dr Pepper, etc.
The gyro and falafel were pretty good. The falafel was freshly fried and a good consistency, but a little dry -- it could have used dipping sauce on the side. The gyro was also decent but a little basic with only the meat, tomato, lettuce, and pita -- it needed a little spice or more toppings.
The staff member offered me some sauce with the falafel, but it was too difficult to hear and understand what he was saying, so I ended up with some drizzle of white sauce. Also, the lids for the cups were clearly the wrong size -- not like, "oh, I'm having trouble fitting this lid on," but clearly too small that it would just fall into the cup.
It's a decent option at Union Station.