Almost always gybe. The trick is to trim hard as you're going into the gybe and release as soon as the wind comes around the back of the sail. When done properly there is very little stress on the rig, even in heavy wind conditions.
It's all about timing as I'm yelling to my crew "trim! trim! trim! trim! trim g$d d&#m it, trim faster! release! release! good job!" Yes, I do have to ply my crew with some spirits after we drop the sails to get them to come back.