You really should do the research on your own to satisfy yourself. This is what I found.
Gamma knife is a one shot deal.
Cyber knife requires several visits.
Usually whatever institution owns either one, will tout either one's benefits, however, they seem to be pretty similar. Cyber may be slightly more accurate. Gamma is more convenient. You need to have good, experienced techs - lining up the beam(s) is critical. Both have radiation leakage.
Complications seem to be the same afterwards (at least for my tumor), however some damage to outer tissues appeared to be slightly less with CK.
They both take some time to work - at least with my tumor.
Thank you for the advice. You are very knowledgeable. My first consult place used only Gamma, the second place advised Cyber, though they used a facility that also had Gamma. How did you find out about their experience, that seems to be difficult.
I have friends that have had it, plus I read a lot. It means reading more of the medical sites such as studies, plus delving a bit past the sales pitch into things.
Some of it though, can seem scary at first, and that may seem to put you off, but you need to know if what you are reading correlates well with the size and nature of your tumor, which is why I cannot respond well or exactly to your question.
I have also attended seminars where doctors speak, and asked them questions.
There is also another types of radiation - proton beam (not many of them). It is more expensive, but it may minimize damage to the surrounding tissue - I don't know how many studies have been done. We did not talk much about it.