heh
In many cases, those kinds of kitchens buy the industrial commercial smokers that are meant to be vented and used indoors. (like potentially in a kitchen that has no outside walls to vent through) I've seen a lot of high-end kitchens with these stainless smokers that look like they've never been used (on the outside), but they do the job and produce great food. That's throwing money at the problem because they have sophisticated thermometers and timers, etc... Chefs often attack the problem using their culinary knowledge of meat and science...
I know what Ponyo's saying about some bbq being bad...the problem with bbq is that it's always a combination of time and temp....you can cook bbq fast, but the inside meat temp has to be where you need it (180-200 degrees) That picture of the beef brisket is an example of a 10-18 hour job if you smoke it instead of roasting it at a higher temp....or letting the meat start at room temp rather than pulling it from a cold fridge and dumping it in a smoker can change optimal cook times significantly in thicker cuts. Guys that are simply selling food to make a buck in a parking lot aren't typically regulated by the health department, so you don't know what temp the meats were kept at before or during the cook. In a restaurant setting or fixed location, they usually have more business come to them and they cook it long before people order. Ribs take 3+ hours to cook... 7-8lb pork roasts can take 6-10 hours to smoke... It's better to know they throw stuff in the smoker or pit and can leave it going overnight. (as my local bbq joints all do....running at 5-6am, you can smell the hickory smoke most mornings)