Dave, summer or winter, I usually start seeing smoke at about the 12-15 minute range in my #2, which is about 70° above ambient temp when I start. I know the #4 is a lot bigger, but the element is too, and the smoke box is just as close to it as on any other model. Is it taking longer than 15 minutes to start seeing smoke? Not that I see a problem with a pre-heat in a big 'ol #4, I (like Gregg) am just trying to understand the benefit.
You mentioned that smoke hitting the cold meat the minute it hits the smoker. I understand your thought process on that, but you also have to remember that the meat temp will climb much faster in a hot smoker, too. It may be a wash, either way. Yes, your impatience to hit 140° will be shorter,
, but I don't think you'll be gaining anything so far as smoke penetration.