Mine was done by a dealer. But, they have a dedicated shop, use good products I was familiar with. And talking to the manger of that shop was very confidence inspiring. She was a petrolhead to the core.
The car still gleams like new.
Once you've driven with great brakes you don't go back. Adding 200 odd HP makes them a must for fast road or track driving.
But I wouldn't just do the rears.
It's mandated I think, in new Euros. Hazards flash on heavy braking. You'll see it on 'Ring vids.
I noticed on my first visit to Italy that many drivers did it manually.