I always torque to specs. Especially if any tires were replaced or inspected using impact wrenches. Few take the effort to use torque bars.
Case in point, I recently bought new tires for my van. When I went to take the tires off to replace the hubcaps, the tire lugs wouldn't budge. They were likely torqued to around 250ft-lbs, when they should be at 95-100ft-lbs. Long story short, I ended up breaking one stem which was embedded in the lug, so had to replace the entire wheel hub. Not particularly difficult, but a pain as it was due for state safety inspection, and wouldn't have passed with one lug missing.
If you buy new tires, I'd recommend going back and re-torquing all your lugs yourself.