Pretty much summed it up ^. I will add The TS2 trigger is slightly lighter as well. For some the extended mag release on the TS2 is too long and gets in the way, it has not been a problem for me. Shadow 2 has an adjustable rear sight. Both feel like cheating but I will give a slight edge to the TS2, less recoil, better trigger, longer sight radius.
But as stated they are an investment and if you could go try both before you buy.