Celtic Health Insurance, anyone heard of it?

Hi All,
Has anyone ever heard of or used Celtic Health Insurance before? I am going to be going to a N.O.W. Nursing Position at a hospital, which only allows 28 hours a week and no benefits, but an increased payscale, so I am looking at private health insurances.
Their plans look pretty good online, but just not heard a lot about them.
Or if anyone has any suggestions, I would be glad to hear from you.
Thanks