While it certainly is a preference issue and both can put out good food, I would argue that gas grilling and coal cooking are in essence different pursuits.
Gas/Charcoal..I use gas because of the wooden deck at home, but have both gas and a small charcoal kettle grill that I use at the cottage. I would like to use charcoal at home, but it is not as convenient. I guess to grill is the most important thing, no matter what type. Sure beats the oven in the house anyday!!
I prefer gas simply because of the ease. Consistent even heat and lighting with the turn of a knob. I have my grill set up with natural gas on a quick connect to my house feed. The ultimate in ease and convienance.
Plus in my mind a smoker box and a few wood chunks makes a great equalizer for covering the flavor differences between gas and charcoal.
I believe that it may come down to a personality comparison. Sure, it is easier and more convenient to use gas(as long as you don't run out smack in the middle of your roast), and it may produce outstanding results with the proper smoker box and all, but could it be that those who prefer charcoal (like myself), enjoy the age old techniques of building a fire, adjusting the air intakes, monitoring the grill temp, make adjustments, make some adjustments again, start up some more charcoal, add some wood chunks, etc. Plus I believe that it tastes better (if only even slightly). Enough of a difference to change "this is fantastic" to "this is the best that I have ever had!"
Personally for grilling - hands down: gas, mine is natural gas connection so I never have to worry about running out in the middle of dinner. However I have a smoker w/ offset fire box that I only use wood logs for fuel. This satisfies the need to be preminative and cook with fire but it takes longer than I want to spend for weekday meals.
Good grief, the whole I'm too lazy to cook with charcoal argument is just getting tired. Just how long do you think it takes to start a chimney of charcoal? We're talking 2 minutes tops. Is it really worth quibbling over 2 minutes for convenience sake for superior flavor? We all have our priorities I suppose. Speaking of convenience, a smoker box is nothing of the sort. While you struggle with a small smoker box burning up your wood much too quicly with little effect and having to refill it far too often, I just throw a handful on the fire and I'm done and on holidays/special occasions I cook with pure wood. For those that contend there is no taste differnce, I challenge you to find many people cooking with gas at any reputable BBQ cook off. You won't find many if any. Not tomention the benefit of having a much hotter fire, especially if you are a practitioner using lump hardwood or straight wood.
I've always enjoyed lighting the coals and cooking over a primative fire. But I don't believe it proper to run down anyone cooking on gas. I had a gas stove once and most likely I'll have a gas grill in the future as a convenience.
If you have a nice BBQ smoking pit should you shame the fellow that only owns a grill.
Some prefer Ford's, I prefer Chevy's...
Let us enjoy our quality time one the grill regardless of the fire below.
My intention wasn't to run people down that use gas so much as it was to defend my method against the WAAAAY overstated and exagerated convenience contention.
I had a dream that one day gas grillers and charcoal grillers could live together in peace, but I guess not. I was not putting down charcoal just stating what I use and why it works for me.