Carlson's "Pattern Plus" choke tubes

Well, I finally got a choke tube rated for Hevi-Shot. The local sporting goods store just opened up a Superstore version of their previous shop and they stock all kinds of goodies but the only choke tubes that they stock are "Carlson's Pattern Plus" choke tubes. I picked one up. The package reads "Ported Turkey Choke" and "For Lead and Hevi-Shot" and it says ".660" on the side of the tube. Any comments on previous experience with Carlson's Pattern Plus tubes? I'm hoping to have time this weekend to pattern the shotgun with it.