I struggled with my decision as well and gave surgery and Gamma Knife lots of consideration. I've suffered from headaches most of my adult life and since getting into my 50's they finally became fewer and farther apart. From all the statistics I've read, people who have surgery seem to suffer more from headaches than those who have radiation. Having said that, not everyone who has surgery gets headaches and obviously not everyone who has radiation develops headaches either. I remember reading statistics indicating that Retrosigmoid Surgery can put you at greater risk for headaches than Translabrynthine Surgery, so there are differences even within surgical options.
In my case, the year prior to having treatment I went through a stage where I had a lot of difficulty sleeping due to headaches waking me up. Lying down seemed to cause headaches especially if I ended up sleeping on my back. I would have to sit up with several pillows until the throbbing went away - and it usually did without needing to take meds. Those particular headaches stopped about 3 months prior to my treatment (Sept. 2013) and I'm glad to say they have not returned. I do suffer from a "wonky" head, most days, but that's a direct result of my balance and occulomotor issues. Thankfully the "wonky" feeling is much more bearable than the headaches and I'm hopeful that it to will disappear in time.
Take your time, do lots of research and you will eventually make your choice!
Best of luck.