On my wish list myself MO.....
What is your thumb safety like? Mine is quite stiff. As far as I can tell I associate that with the hammer spring being a heavy 18-20 lb unit...a la, the extra hammer pressure on the sear is pushing down the leg of the sear spring harder on the shaft of the safety. The reason being that when the pistol is at half cock, with less spring compression, the safety clicks on and off considerably more easily than when at full cock. And the thumb safety on my Shadow 2 is quite easy to engage/disengage (13# hammer spring in that). This is either with the stock safety lever on the TSB or a replacement Shadow 2 safety lever. I even polished it up.
It was the same when I was checking out a regular Tac Sport in a gun shop, but then I tried a friend's regular Tactical Sport just last night....he didn't change any factory springs and his was nice and easy like my Shadow. Maybe it just worked itself in after a lot of shooting?