I have two 6378 holsters one for my full-size HK USP40 and the other for my GLOCK G26. They come set up as paddle holsters, but also include a belt loop attachment which I switched to. I think switching to the belt loop makes them very similair to the 6377 if not identical.
I really like the holsters and find the ALS very easy to use and as you said I prefer it to the SERPA which I also own. The holsters ride pretty close to the body and conceal about as well as any OWB will. The workmanship seems good and the price seems pretty decent.
A major source of objection to a free economy is precisely that it ... gives people what they want instead of what a particular group thinks they ought to want. Underlying most arguments against the free market is a lack of belief in freedom itself.
- Milton Friedman