I have a pair of GSP in a 75g - they were the reason I set up a SW tank. I had them in a 20g brackish (.5ish) for a few months while I researched, then drip-acclimated them to 1.25 SW tank over the course of a day.
It's a mixed reef set-up as through my 1 year newbie experience, I've added a bit of everything to it, including a few SPS. If you do your research and be mindful of their needs, there is a good chance of success. They are amazing fish.
Re feeding, I find that easy and no food gets wasted, haha. They peck at the rocks so no need to deal with teeth issues.
Btw, they share the tank with:
- YWG/pistol pair, 2 ocellaris clowns, long nose hawk, mandarin dragonet, tail spot blenny, flame hawk (introduced in that order)
- 2 hermits, 3 snails, 2 conches, tuxedo urchin (all original CUC crew)