Safariland J-C7 comp I for speed loaders. They hold the rounds in better alignment than HKS and all you do is insert and PUSH.. the rounds drop right out without any twisting like the HKS requires. The comp I are a little more compact as well.
If you want something that disappears in a pocket then speed strips. I've only tried the Bianchi brand, they work great. Slower to reload but once you use them a few times it's not that slow. I load two at a time until the last round, if you really needed a quick follow up shot you could just strip two rounds and then finger the trigger until you get bangs....