<-- My '74 LP Deluxe in the profile pic here has been through the wars.
Back in '81 or '82 after a gig, we had to pack up and clear the stage quickly after our set, so my drummer helpfully suggested that he could pack my guitar away in the case while I unloaded some other gear.
TIP: NEVER get a drummer to pack away a guitar.
When I got back to my room that night, I opened my case to do my usual post gig clean down of the guitar, only to notice that he had coiled about 3 of my cables up behind the headstock before he closed the lid, and it was now.... unsurprisingly... snapped. It was just the front laminate holding it on !!
Luckily, another friend recommended I take it to a violin repairman that he knew. This repair guy did a terrific job of glueing and refinishing the headstock so it looked good as new. You have to look really hard to see the crack line on the back now.
In conclusion, I believe the headstock is MUCH stronger now. This guitar has spent the last couple of years hanging on a wall hanger behind my desk so I can grab it quickly. The two prongs on the wall hanger contact the headstock EXACTLY where the break was. Never had an issue with it.
As whether the guitar SOUNDS better? No idea - it still sounds good to me, and I never did an A/B test before and after it broke! 
There is nothing about the sound of the guitar that I dislike now - it still sustains and has sweet tone.
JBLP Gold Top #129 - redubbed "#1 in Oz"