I had SRS three months ago to treat an AVM on my left occipital. This was my second AVM- the first was on my right occipital and I lost 25% of my vision when it ruptured in 2024, requiring an emergency craniotomy.
The SRS procdure itself was fine, really- a long day in hospital but my consultant warned me that boredom would be the biggest risk during the surgery and he wasn’t wrong! Totally painless, no sensation at all. Fortunately the technicians had a radio hooked up in the treatment room and let me choose the station- indie rock all the way through!
I had a Leskell-type frame fitted before the operation, and while I was certainly pretty scared as I was being wheeled into the framing room, I’d describe it as more ‘uncomfortable’ than ‘painful’. The pressure from the pins as they were torqued up was an unfamiliar and unsettling feeling, but it wasn’t excruciating and within a minute or two I no longer felt it.
Best sensation ever when they finally took it off at the end of the day, though! A team of nurses leapt into the room like a Formula 1 pit crew, undid all the pins in one coordinated move, and lifted it away all in about twenty seconds. 
Other than that, I had a bit of minor claustrophobia in the pre-operation MRI which I put down to the fact that the frame was rigidly clamped to a fixture, so I was firmly locked in place inside the tunnel. There was also a cerebral angiogram, which is never fun but beyond a few strange sensations I didn’t feel a thing this time round.
The pin sites healed up within a week of the surgery and the anaesthetic in my scalp took a few weeks to wear off, but compared to the recovery from my craniotomy it was all blissfully easy!
The side effects I was warned about didn’t come to pass, thankfully- swelling on the affected area of the brain was a possible concern which would have meant risk of further vision loss, as was potential left side weakness (based on the adjacent area the swelling would be pressing on).
Overall, while I’m certainly no medical expert on SRS, as a patient I found it to be really straightforward. A bit of an anticlimax after four weeks of worrying, if anything! It’s a fairly well established and mature treatment now- I seem to recall being told that the hospital department that treated me (Sheffield, UK) had been delivering it for 40+ years so even though it looks and sounds pretty sci-fi there isn’t anything experimental or unproven about it!