OT - Blackstone griddle

I almost went with the Camp Chef Somerset IV as mentioned above.  As mentioned in that post, you get very hot burners... If I went that route I would have also bought the heat diffusers that Camp Chef makes and installed them, I've read that without those you can end up with big time hot spots on the griddle and therefore if you're making something big that covers the entire surface, like say combination fried rice, you can have a tough time with uneven cooking.  My understanding is that buying the extra heat diffusers is almost a must with the Camp Chef.  Again, this is just stuff I've read on other forums from other owners, I haven't actually used the Camp Chef.  YMMV.  Maybe @deekortiz3 can speak as to whether or not there are hot spot issues on the Camp Chef sans diffusers.

Camp Chef also makes a portable series.  If I went to more tailgates and stuff, I would've gotten that.    I knew going in that 95-100% of my griddle usage would be at home though. The Blackstone is portable enough that you could take it to a tailgate though (I've seen it done).  The heaviest part BY FAR is the griddle top itself, and it is removable. I knew pretty quickly a backyard unit suited my needs better than a portable one.  You can also use the Camp Chef without a griddle top as an outdoor stovetop.  A nice bonus, it just wasn't something I needed for cooking at home.  

I ultimately chose the Blackstone because I could get a good deal on it, and there was a demo model I was able to go see at a Lowe's down the street.  I also wanted a griddle I could buy in a store and take home in my own truck.  I have horrible luck with shipping damage, and almost all of the negative reviews on these units are about shipping damage.  That said, I found the blackstone to be well-packaged, so maybe that is an old issue they've already addressed.   In the end I realized I spent too much time worrying about total BTU output, etc.  Can some other models get hotter?  Yes.  Do I need a hotter griddle?  Absolutely not.  Most of the time I have to cook with the BS griddle on low-to-medium heat so that I don't scorch food.  The thing gets more than hot enough for me.  I only crank it to full blast when I'm searing meat or cleaning the griddle.  (Having the multiple burners for a hot side and a cool side gives you full zone control when you need it).

@texaswig BlackStone sells the grill box you're talking about too.  You can have that feature with either model, so the can be used as a lidless gasser, so to speak.  The only feature Camp Chef has that BS doesn't is the ability to use it as an outdoor stove.

I don't think there is a wrong answer as to which brand you should buy.  But I would recommend getting one.  They are an absolute blast to cook on.  Make sure you buy a second set of spatulas though, because your family and guests will inevitably ask to give it a whirl when they see the thing in action.  There is enough griddle space for two people to work side by side.

I especially use the Blackstone griddle when time is a factor.  I'm a busy guy with a young family and on weeknights after work I can't always go remove ash from the egg,  fire it up, wait for it to heat up, let all the lump chemicals burn off for 25 minutes, and THEN start cooking...  I've got a young daughter and often her bedtime comes around before I finish.  She has never once complained about 2nd day Green Egg leftovers though, she loves em!  With the griddle, I fire the thing up, let it heat for 5 minutes, and the food goes on... It cooks SUPER fast, and then I pull the food off and have my wife plate it... during that time I crank the griddle to full blast, scrape the remnants into the grease trap, and then use a soaking wet rag and one of the spatulas to clean the griddle.  The whole process takes me like three minutes.  Then I shut down the propane supply and go in and eat.  After dinner the griddle is cooled down, so I apply a thin layer of vegetable oil all over (prevents rust) and then put the cover back on.  Boom.  Done.  

I can cook and clean on the griddle faster than I can with my stove and sink.  For me, time is a huge factor so that I can nail dinner during the window of getting home from work and kiddo's early bed time.  The griddle gets a lot of use during the week, but the BGE gets used a ton on weekends.  I see a Mini Max in my near future for some faster weeknight egging though.

I've rambled a bit here, but I hope this was helpful.  If you buy the griddle, make sure you get the right spatulas, two squirt bottles (for oil and water), something to chop with, some scrapers, and some rags you're willing to scorch.  BlackStone sells an accessory kit with most of that stuff at Lowe's.  Handheld construction scrapers from the paint department work great for quick cleaning too (get the more rigid, non-floppy blade).  If you have that stuff and a full tank, you'll be ready to season the griddle and cook on it right out of the box.