I've seen posts from people stating that RBI effectively makes kaf chips useless for science images. I've been using kaf chips for a decade for 1% photometry and it's not affected me as yet.
Here's a useful analysis:
http://canburytech.net/QSI532/RBI.html
The effect - at worst - seems to be measured in millimagnitudes. Not sure how many amateurs are delving into that level of precision in photometry!