I'd be happy to have that extra 5 minutes to figure out what to do next. Make sure you get a quality one that is comfortable. You should also wear it all the way up and down the tree. You will get use to it after a while and it will be second nature. I've been wearing one for years and just was able to influence my buddies recently to start wearing them.
A waist-belt harness may do you in after a time,but I use harnesses that are like a parachute harness.Some of the guys who were shot down in Vietnam spent a long time hanging in their harness.Some of the D-Day paratroopers hung all night or more and survived.