I have a new Rockwood on order that is supposed to come with one. I don't have it yet. However, I do already have a 17" Blackstone. The griddle that comes with the Rockwood is supposed to be a copy of the 17" Blackstone.
I personally love mine. It is extremely versatile. Since it is a copy of the Blackstone, I am not sure if the Blackstone accessories fit, but if they do, they sell a hood for it.
If you have a dollar tree by you, go purchase 6 or 8 Chopper/Scraper. They are $1 a piece. They can hang over the edge of the griddle and block the wind so the griddle doesn't blow out. They are also great for scraping it off after cooking.
There is also a Blackstone users group on Facebook that may be worth joining. Lots of recipes and idea's on there. I have a 28" one for my house and the 17" from my old trailer.