To me, BBQ grilles are made for hamburgers, steaks, and such. Smokers are for long term cooking to gain the smoke flavor in the meat.
I have a large 5 burner gas grille that I use as mentioned. I also have a large stick smoker that I use regularly also to smoke pork butts, ribs, brisket, whole chickens, and other meats. Smoking is an art to get the right flavor and tenderness in your meats. It's not something you just put on and leave it. Like I said I have a stick smoker( uses logs ) I do not have a built in computer to maintain temperature like pellet or electric smokers do. I don't feel like that is true smoking. I get fire going, set my dampers to maintain my desired temperature, throw on another log as needed, watch my temp, and after a certain period of time I wrap my meat and place back on until done. The eggs are nice and I know a lot of people that have them but they are very expensive and you have a pretty limited amount of space. I almost bought one when I bought my smoker but decided I liked the challenge of a stick smoker. I try new ideas and get a little better every time I smoke. Electric smokers aren't really smoking at all to me.
Anyway, way to long here, but that's my take on smokers and grilles. If you like old school, buy and good stick smoker for long smokes and gas grilles to cook hamburgers on.