I'm a Phoenix native who frequented the Cajun restaurant that occupied the location before Grassroots. I moved away and have come back to find a new restaurant in it's place!!
I was impressed with the renovations made to the location - it was clean, stylish and inviting. The only problem I had was with the parking. It's no fault of Grassroots that the construction was going on, but it was way too difficult to find parking. It was worth the wait though. Make sure to have a plan before showing up!
I ordered the Grilled Angus Burger sans Mayo with the Pork Belly added on, fries, and a side order of the Southern Baked Beans. The burger was cooked well, and the accouterments we fresh. My only concern was that I asked for no Mayo, but there was a glob of it inside the to-go dish. The fries tasted like they were cooked in fresh fryer grease (a good thing!!). The beans were....interesting. They were a bit too "sour" for my liking. It tasted as if they added some type of soda pop or a lot of un ripe tomatoes to the base. They were good, but nothing I would rave about.
The to-go process was simple and quick, and the staff were very friendly. I really like the gentlemen who was working the bar - he was helpful and very kind.
Overall, it's a good place to try if you're looking for something new, but not a Must Have in the Phoenix Restaurant scene.