I don't do a full-on force carb, but I do a bit of an accelerated carb schedule. I use about 30 PSI to seat my lid, then shake for maybe a minute or so. Then I back the pressure down to about 20 PSI and lit it sit at about 36-38F for 1.5 to 2 days. After that I back it off to 12 PSI and check back in a week or so. By going hard the first couple of days it does seem to shave off a few days until the keg is carbonated to my liking, but I don't push it so hard where I'd have to worry about overcarbonation if I accidentally let it go at 20PSI for a couple of extra days.