Lots of opinions, and no doubt why CZ makes a bunch of different models (just wish they were all in stock at a store nearby). Some thoughts:
I think the general consensus is a .22 lr achieves max velocity in a 16" to 18"barrel. Tests results I've read of, have the velocity then staying reasonably close to the same until about 24", then velocity drops off due to the additional barrel friction. Will a longer barrel be more accurate? Well, logic suggests there is an advantage with a longer sight radius using iron sights. Since most are using optics, a shorter barrel, all else equal, should be stiffer and have less "whip" or vibration and harmonics amplitude than would a longer barrel of the same dimensions and material. If one is adding barrel devices, such as a suppressor, the shorter barrel gets the nod as the longer barrel tends to get unwieldy with the additional length of the can. Most all my .22 shooting is suppressed.
The At-One good: It's adjustable, and I do not notice the adjustment points moving once they are set - mine is as solid as can be. Getting good cheek weld, even with a lower scope mount is no problem. I like the look of a traditional walnut stock, but the laminated stock of the At-One is no doubt stronger and less subject to dimensional changes due to temperature and humidity. Most all the broken wood stocks I've seen, seem to break just aft of the tang, along the wood grain, where the wood is thinner and stress on impact would be greater. The At-One is hell for stout.
The At-One not so good: Unlike the other 457 models (not sure about all, but most anyway, have plastic pillar bedding), the At-One doesn't come with any pillar bedding. You can add them of course, and I did that on mine, getting them from Pete's Pillars on eBay. If I'd of had my lathe at home then (my tools were at the airport and I was down for maintenance, I'd have made my own from stainless steel. (FYI, aluminum has twice the thermal coefficient of expansion as does steel, plastic is much higher than metal, so CZ's choice to use plastic is a head scratcher).
