I went to CAMHS but not for anorexia.
CAMHS is a really variable service, some clinicians are brilliant, some teams are brilliant, some areas have more funding available than other areas.
I think most people will experience a bit of a mixed bag- they will have some good and some bad experiences. It's unlikely that you will be 100% comfortable with them all of the time and this is partially due to your mental illness.
Some people do have an absolutely awful experience, I did but I am alive right now and I don't think I would be if they hadn't intervened, so I suppose they got something right. However I think they've actually traumatised me.
At the end of the day for most people it's worth attempting to get the treatment they need. A mentally ill teenager will become a mentally ill adult- it's a shame to loose out on having a good life.