My rule on Heavy. 1) If I get there and no enemy is around, I will wait 3-5 seconds for teammates to get into range. If no one is there I am pulling it because chances are I have enemies bearing down on me within 2-3 seconds after that and my position is usually exposed. 2) If radar starts showing red I pull unless teammates are engaged with enemy 3) If Heavy location is secure, such as A side on Rusted Lands, l'll wait longer.