Rich, I'm not sure what you are saying...well, maybe sort of.
The laser will tell you with (literally) pinpoint accuracy where you are "weak". You feel air movement, but do you know exactly where it's coming from ? I hear alot about feel air movement..it's "coming from the slide". Well, ok...but is it coming from the whole slide, or maybe from the corner(s), or from the top, or...? I think one thing people sometimes fail to realize is that every little bit helps. Maybe walls are r19, but a slide joint is r3? There are cures for alot of this, but I'm sure there are a lack of cures for some. So, for example, if you are wintering in FL and you feel a "breeze" coming from a slide...being as you maybe stationary for a month+, can you go outside and run a strip of clear packing tape over the slide joints? Or maybe it's in the corners, and you can stuff a piece of non-adhesive weatherstripping into the joint. Outlets are another biggie. One nice thing about a laser is, once you pull the trigger (and hold it down), you can "drag" it along a stretch and tell exactly where the difference is.
Hey, I don't even have my Monty yet...but when I do, I will surely be testing and trying to improve on the insulating of it...because it probably makes just as big a difference in a/c as it does in the heating.
If your point is that they don't put adequate insulation in the walls,ceilings and floor....well, ya got me there !
But whether a stick built or a 5er...there's always room for improvement.
See ya soon !