I bought one of the Neos mags from here and tried it in my Colt .22 pistol at the range on June 15, 2010. I put 120-rounds of Remington Thunderbolt (low-end ammo) through the pistol, 40-rounds each through the pair of Colt mags that originally came with the pistol and 40-rounds through the new Neos mag. The only feed failures that I experienced while using the lower quality Thunderbolt ammo were with the Colt mags. Except for the black plastic floor plate, the Neos mags do look to be identical to the Colt mags. The Neos mags also seem to do a better job locking in the slide stop after the last round than do the Colt mags, which seem a little weak, often barely pushing the stop lever into the slide stop notch.
Since a 40-round test of the Neos mag is hardly exhaustive, I am not going to guarantee to the entire world that it is perfect in fit and function for the Colt .22. However, the next time CTD has the Neos mags in stock I am going to purchase a couple more of them.
Why did I only shoot 120-rounds through the pistol for this test? The lower quality Remington Thunderbolt ammo leaded the bore of the pistol so badly that accuracy disappeared; the slugs were keyholing into the target (more on that in a subsequent post).