I know the original discussion was settled a year ago but it seems to me that steel linings are used in fast draw where retention is a long distant second to drawing speed. Where the holster is just a bucket to grab from. In 30yrs of using leather holsters, most good designs will retain the gun they're fitted to without retention straps or thongs. The last Slim Jim I made, for a Colt 1860, will hold the sixgun in place even upside down. I almost never use the retention on my Slim Jims, Threepersons, Austin or Mexican loop holsters or the Mernickle PS6 concealment holster but they're only used with the guns they're fitted for. Although the aforementioned sight lock or a sticky lining like pigskin might be a good idea. Definitely wouldn't want to use a smooth lining.