I bought my BGE over 2 years ago, and, yes, it was a big investment, but any outdoor cooking vessel that is going to last more than a few year is going to be. You can't touch a decent gas grill for under $700-1000 and I believe the pellet smokers are in the same neighborhood as the Egg, and much less versatile. Anyway, it's an incredible smoker and can maintain low and slow with little to no tending for very long periods of time. It's extremely efficient. I normally smoke while I sleep. I'll get my fire started and the temp stabilized in the early evening, throw on the meat, and check it right before I go to bed. I've not had a fire go out or any issues with temp controls. I've had my large Egg go over 24 hours straight without reloading. If you like tending your smoker every hour or two then this won't be your thing. Someone else mentioned the Stoker or Guru. One (or both) not only control the temp, but you can also access and control them thru the internet if you have a wifi/network system set up at your house. I haven't pulled the trigger yet, but it's on my short list! That takes care of smoking, on to grilling. The geometry of the dome helps keep foods moist and cook evenly. I've not had as good nor consistent results on any other grill. The ability to get the grill to 800* plus to seer and then shut the vents to finish a steak or roast is awesome. My wife figured it was just an expensive grill, but she changed her tune the first few cooks, not only due to the results, but also due to how easy it was to start and cook on. Also, it should last a lifetime and comes with a warranty to help that along.
And, no, I'm not just an Egg fanatic. I also have a JennAir natural gas grill that I also enjoy using and I built a wood fired pizza oven a few years ago.
Here's a pic of my outdoor kitchen I built last year.
Here's the WFO