I have several Gotham Steel pans and the square griddle is a great addition.  It absolutely is non-stick just like it says.  Just like with other non-stick pans though, always be careful not to use metal utensils or else you run the risk of scratching it.  

Another tip is to wash it by hand rather than using the dishwasher.  I'm sure running it a few times through the dishwasher won't hurt it but too many times could reduce the effectiveness of the non-stick material.  

Lastly, I'd recommend pouring good quality olive oil in the griddle, warming it up on low-medium heat, spreading the olive oil around and then removing it from the heat to let it cool.  Doing this after several uses seems to help preserve the non-stick features.