I thoroughly dislike my 6377 ALS (same design as 6378, but belt loops instead of paddle). The retention grabs the actual slide (but is sloppy for my 1911 and it clicks when i walk quickly or run) and the release button is too small and too close to the body (or too close to my love handles, as the case may be).
However, I love my 6280 SLS I recently got for my FNP9. It has better retention and is easier to release and draw as the release button is bigger and farther off the body.
opticsplanet is where I order my safariland stuff.