i went to one once, and they cut me to shreds. I have extremely sensitive skin at the best of times, it's easilly roughed up by a blade held at just the slightly wrong angle. I also have odd hair on my neck that grows in several directions, and years of learning my own face has taught me how to deal with this. They just ploughed on, and as a result, my neck was covered in cuts, nicks and redness. My neck looked like a plucked chicken.
Never again!!