Glass pans have always given me soft brownies without burnt edges. My oven runs hot, so metal would overdo it. Maybe it's more about heat control than the type of pan.
Oven thermometers are cheap and will save you a lot of guesswork. Glass does insulate more, so if your oven runs hot, you're right to use it. Just drop your temp by 25 degrees next time you bake in glass. For metal pans, you can always wrap the outside in foil to slow down the heat a bit. It’s all about playing defense against your own appliance.