I can’t speak directly to the 182 issue regarding vg’s. However I operate a Cessna 172XP (210hp) and when I purchased it the airplane was stock. I installed the sportsman stol kit which is a leading edge cuff and gap seals on the ailerons. We didn’t loose any cruise performance and the slow flight performance is so much better. Towing performance is much better with a substantially shorter takeoff roll and we can tow Schweizer’s as slow as we care too. Aileron authority is much better since adding the kit.

Having flown airplanes with vg’s I can attest to the fact that they certainly have a positive effect in performance and handling.

These improvements to slow speed handling not only improve the towing performance but also increases safety for the towpilot in normal and emergency situations.