I used one on my P-64 (RIP, was traded away for some mechanic work) and it was a perfect match. I carried safety on at 3 o'clock. It was comfortable, stayed in place and concealed almost as good as my LCP worn in a IWB holster.
Using something like a ClipDraw with a gun like a Glock, where there isn't a switch somewhere as a traditional safety, isn't a good idea. Using one with a large framed gun isn't gonna be fun either. I like the product, but it excels in little guns (with a safety) and deep concealment.
I thought I should mention that the customer service I received from ClipDraw was exceptional, I'll be buying another when I replace the P-64.