I went on a Friday evening around dinner time and expected great things - I'm a big fan of Stack'd in Shadyside also and their burgers are yum!
First of all our service was terrible. I hate to say that because the waitress was very nice and friendly but I think the place was just highly understaffed with way too many customers and not enough waiters/waitresses to handle them. It was over a half hour between the time I sat down and the time I actually was able to even order anything (maybe a 15 minute wait just for my glass of water).
I ordered wings to share, half Thai Chili and half OMFG! sauce (both of which I've had at Stack'd) and though I am aware that they are labeled spicy - usually my friend and I can handle spicy. However these were WAYY too spicy to the point where you could tell the flavor was good but the fire was just a bit much.
They also lost my other friend's burger order and had to rush it later after the rest of our food had already been brought out even though he turned in his order slip along with us.
Then when we were almost finished eating and ready to go, the waitress came out with 2 more wings saying the kitchen had dropped them (on the floor?) and decided to make us new ones give them to us like 20+ minutes later? We hadn't noticed because the menu doesn't say how many you are actually supposed to get but I thought this was strange - though it was nice of them to give us the wings even though we didn't ask for them.
I don't want to be too harsh and ideally I would leave around 2.5 stars but since the wings were good (albeit too hot to handle) I'll round up to 3. But the establishment needs to pick up the pace a bit because the service was far too slow and I spent a good chunk of my time here feeling frustrated.