I found it very interesting. I have heard a few fellow shooters complaining that their filters actually degraded the image and had removed them completely. On inspection I found they were cheap non-branded filters.
I mainly have either Hoya or Sigma but I usually sell a lens with the attached filter so most of my old ones have now been replaced with newer Pro1 or HD usually bought when on special offer or bundled.
Only a Tamron 16-300 left sadly. Sony cannot supply what I want so rightly or wrongly I've branched out to someone who does and I'm very happy.