I had my 1st holster just shy of 2 years. It was designed so that it didn't wrap all the way around the light...in a "C" shape. When I got it, I thought it was a tat on the loose side so I heated it with a hair dryer and formed it closed a little more so it was a tighter fit. I never noticed it loosening up over the time I had it, up until the clip broke.
The version I have now, much like the design of Henry's, wrap all the way around the light and are shaped like a "P". There are screws and rubber spacers that allow you to adjust the amount of tension to your liking. I've only had this holster for 2 months, but expect many, many years of service from it based on my experience of my 1st holster.