I think both are good depending on situation, when i was an apprentice about 20 or so years ago a Jaguar XJ6 came in with rear 1/4 panel damage, when examining the new panel which had part of the rear screen surround, fuel filler & most of the arch into the door shut i was a little dazed.
Once all the parts were stripped i was told to hand cut the old panel in half & then the new one in the exact same place, If i made a mistake it would come out of my wages
. Well i did it with a 100% perfect butt joint, not sure how that happened to this day! but to conclude the story the guy dishing out the orders proceeded to gas weld the butt jointed panels with such a fine weld & no distortion there was minimal re finishing to do. A good lesson was learn't that day & boy did that save some labour time, the same guy taught me how to gas weld something you never forget like riding a bike!