I believe the brand of chicken you're referring to is Bell & Evans, which we buy from time to time, and almost always when we're doing a whole chicken rather than just parts such as breasts, legs, etc.
I'm certainly no chicken processing expert but, as I understand it, following slaughter a chickens internal temperature is approximately 100°F, and USDA requirements stipulate that the chicken must be chilled to at least 40°F within 4 hours of slaughter. The common practice in the U.S. for many years has been water chilling where the freshly slaughtered chickens are submerged in giant community vats of ice water until the objective is achieved.
Air chilling, which has been the common practice in Europe and other parts of the world for over 50 years, has only made slight inroads in the U.S. in the past 15-20 years. I believe Bell & Evans may have been the first brand in the U.S. to adopt this practice, but if not, they're certainly the largest producer utilizing the process. Air chilled chickens are individually hung on an overhead conveyor and cooled by passing the birds through several chambers for approximately 2 hours where puffs of increasingly colder, purified air is used to chill the meat - resulting in no added moisture, stronger flavor, firmer texture and less chance for cross contamination. The birds also tend to cook somewhat faster with the added bonus of skin that always crisps beautifully.
To me, there's no doubt that an air chilled chicken is markedly better than water chilled one. The matter of whether or not they're worth the additional cost is an individual one but, to me, they definitely are.
Should you decide to try one i suggest that, at least initially, you season and cook it simply. It would be counter productive to add a bunch of additional flavors that would mask the flavor of the bird.
