I've seen mixed reviews on the KCI mags.
Frankly since the AWB expired I buy only factory mags or mags made by a current OEM supplier. In fact, I'll take a used factory/OEM mag over a new aftermarket mag.
Admittedly the price isn't as good as the KCI mags, but this is a pretty decent deal on G19 mags.
http://www.cdnninvestments.com/gl199mm15drf.html
If you're set on buying the KCI mags, I'm pretty sure the link below is selling the same mags and definitely for a much better price.
http://www.cdnninvestments.com/gl199mm15nom.html