I was wondering about this GK vs CK the other day.
I was checking to see if there was a CK anywhere in Arkansas (doesn't seem to be) and came across information about GK on a website for UAMS (University of Arkansas for Medical Sciences) here in Little Rock.
They have GK, but not CK, and their page was basically touting GK over CK, saying it was more accurate, etc., and talking about the advantages of the fixed head frame over the molded mask used in CK. I was surprised that they were downplaying the advantages of CK.
But, of course, on other sites, like for the Barrow Institute, some of the very things UAMS was listing as negatives were stated as positivies--no frame, for example
And Barrow also has GK, so it wasn't really trashing GK treatment, either, simply offering either treatment as an option depending on what needed to be treated, etc.