There was fastener load information on one of the TV mount sites with surprisingly large tensile loads for drywall using togglers. I would guess that those high load figures [up to 265lb tensile in 1/2″ drywall] are probably for short duration loads and concerned with pulling the toggle through at a point close to a stud or joist, but it is still way more than I would have expected. It seems that they advocate mounting up to 150lb TV’s on drywall alone, although they may mean just the static wall mounts instead of the swing-arm mounts. http://www.mycablemart.com/store/cart.php?m=product_detail&p=1281 I weigh a lot less than 265lb, but I don’t think I’ll try standing on the drywall between ceiling joists anytime soon. 🙂