I have the Fons and Porter one with grids that I hang up. I got it as a gift. It is nice but I wouldn't go out of my way to spend the money for it if I could do something cheaper. I never use the grids and don't think they are all that important. When you put your blocks on the board they are not the size that they will be once they are sewn together so I don't see where the grid helps any.
One suggestion I have however is to make your design board bigger than you think you will need because even then it still won't be big enough!