UPDATE
Well it has been a year.
I now have a couple J Frame Jet Loaders. They do indeed work well. They are also useable for concealed carry by those who wear a holster on the belt, and not bad at all for jacket or vest pocket carry.
This is a picture of a J Frame Jet Loader in a Big Creek Belt Carrier. An HKS 36 is also shown, and will also work well in the belt carrier.
I normally wear a Pancake holster at 4 O'Clock. I also carry a speed loader infront of the holster. I do this the same way anytime I belt carry a revolver which can be a 442, SP101, K Frame Snub or my WC GP100. AND this is also where I carry my Primary Reload when shooting Defensive Pistol, and ICORE Matchs. No fumbeling around, my concealed carry reload is in the same location as my match reload.
Back to the J Frame/SP101.
We are pretty much limited to the Safariland Comp I, HKS 36, 5 Star, and the Jet Loader. Of the 4 listed the HKS 36 and 5 Star are turn Knob style requiring you to hold the cylinder to release the cartridges.
The Safariland Comp I a push to release style requires you to grasp the speed loader by the body. This requires some dexterity to keep your fingers away from the side of the revolver. One draw back to the comp I is no great way to carry one on the belt where it is fast to get into play.
The Jet Loader is grasped by the knob, and extracted from the bely carrier. Holding it by the knob positions your hand far enough above the cylinder to really speed up the reload.
No issues with finger clearance along the side of the revolver.
I have only found a couple sources for the Jet Loaders.
Pistoleer, and Power Custom. They are a little on the expensive side when compaired to a Comp I or an HKS 36, but not all that bad if you compair them to a semi auto magazine.
Is the Jet Loader worth the expense?? I guess it depends on just how important a Fast Fumble Free reload is to you.
At the moment I have 2 of them. One is in my box of speedloaders I keep to check the fit on the Kydex Belt Carriers I have started to make. Leaving only 1 for concealed carry and match use in BUG Division. I am planning on getting atleast a couple more on order shortly. They are worth the expense to me.
Bob