I don't think it matters for the typical BBQ meats like butts, briskets, chuck, ribs, etc. But, for some meats the results are better at a specific temp range. poultry, for example, is much better at higher temps, and a rib roast is better at lower temps, IMHO.
I'm a believer in letting the smoker cook at the temp range that it prefers. Almost every cooker has a temperature where it just seems to be in the zone. Figure that out and don't fight it just to cook at a specific temperature.