Yes, I have had that treatment, in Oxford. I chose it because it offered a more targeted approach ( a loop in my bowel plumbing meant that my local onco team could not get a sufficiently clear shot at the target) and I was not keen on RP.
The experience itself is a breeze- collected and taken home by car, treatment times to suit me, everything on schedule, just 5 sessions to deal with and Pink Floyd on the headphones. No discomfort on the table unless you are claustrophobic. Only one of the sessions was a bit fiddly in that they had to pause to deal with an errant gas bubble, but I was kind of pleased in that it suggested that the real-time positional monitoring was working as intended.
Vey few after effects- I just had 2 days in the week after the last session when it was a good idea to stay close to a loo, but apart from that- nothing. I have had, and still have, more persistent effects from the 2 years of HT which preceded it.
Has it worked? Who knows. It's 10 months on and my PSA is close to zero but that may be the Zoladex still hanging around. I'll know a bit more by the end of the year when the last remnants of the HT should have faded out. With any form of RT you don't have the neat finale of the surgeon coming alongside next morning and saying 'Congratulations, its a boy'- you just have to sit out the sequence of blood tests. But I am content with the choice I made. I had the rather large benefit of never being emotionally savaged by the whole diagnosis and decision-making thing, so although it took me quite a long time to get to the point of treatment, the low key nature of it in the end suited me nicely.
Shout if there's anything else you need.