First of all, I already have a Weber kettle for charcoal grilling and smoking. I don't need another. I also lack space for a wood-fired uber-grill. This is strictly going to be about gas grills and griddles for outdoor cooking...
Wifey wants a gas grill for the ease of use. She has no interest whatsoever in dealing with charcoal or wood, so we don't grill if *I* can't get the grill started in time for it to be ready to cook with by whatever arbitrary time we set. A gas-powered implement would allow her to take over some grilling duties when I'm otherwise indisposed.
So, that aside, which would you go with? I'm leaning toward the griddle because most of what we cook on the grill today are items such as steaks, burgers, hotdogs, etc. The griddle would facilitate cooking masses of peppers and onions (those we do on the stove today). We could expand our repertoire to cheesesteaks, quesadillas, bacon, etc.
I got a chance to use my buddy's huge Blackstone griddle one weekend and immediately saw the utility. We cooked burgers, brats, and mass quantities of peppers and onions. The burgers were as good as any off a traditional grill IMO.
However, wifey's not impressed with griddles. In her mind, it's no different than cooking on a frying pan in the house. To an extent, she's right, but you're not smoking up or heating up the kitchen. You also have more space to work with. And...you're outside!
I found a combo unit at Cabelas that has a decent amount of traditional gas grill space and a decent griddle space, both with separate burners (two each, 15k BTU each). It's $300, but I'm not sure it's at the same quality level as a dedicated grill or griddle in that price range. The grill lid felt a bit thin.
Thoughts or comments?
Chris