FWIW, my POH (PA-28 181) says the plane gets a 8 kts speed improvement with the pants on. I painted stripes on the wheels to know when fill valve was at bottom and then stretch it for 2-3 seconds to fill/measure.
Ever think about doing it yourself?
It is allowed by FAA if you own the plane. Did mine in 30 minutes (Archer II) and did the metals sample kit at the same time. You will need a safety wire and wire wrapper but they cost less than an hour of mechanic labor.
