There are two different definitions of the term BBQ.
BBQ the way most of us define it is actually known as "Grilling". High direct heat for steaks, burgers, etc.
Proper BBQ is low and slow indirect heat which can be smoky or not.
You can usually do both with any grill, but they will typically only excel at only one or the other. I personally have two grills, a propane one and a charcoal one. If I am in a rush and want some flame seared steak for supper, or it's wintertime, I use the propane. It's quick, clean and gets the job done. If I do not need to rush, want to enjoy the cooking process (and a couple beers) and enhance the flavours, I use the charcoal as a grill. Then there's the days where I just gotta have juicy, tender, slow cooked BBQ beef and there isn't a restaurant in this country that I have found that does it right. That's when I turn the Weber into the ultimate BBQ tool by adding the "Smokenator 1000".
http://www.smokenator.com/You can see the extra baffle on the side that keeps the charcoal from applying direct heat to the meat. It also has a water pan that keeps the moisture level up so that it doesn't dry out.
12 lb brisket. Took about 10 hours of cooking and 2 hours of resting to be fall apart tender and juicy. I didn't take any pics once we sliced it up and started eating, it was awesome. I have been on the hunt for a place that I can go to get brisket that is that good, and I haven't yet been able to find one. I am salivating just looking at my pictures again.
In my mind the perfect comprimise is a cheap propane grill and a Weber kettle. There is so much aftermarket support for the Weber kettle grills I wouldn't have even considered any of the other brands out there. It's a great tool that takes some skill to get it to work the way you want it to, but when you figure it out, it's unbelievably good.