I have only experienced one 5 star, and that was a Mjolnir. I will say that there is noticeable improvement with each knocking in session. They feel pretty unresponsive compared to the likes of CA bats, but I sold my Mjolnir (regrettably) and noticed that with a throw down session, every 10 throwdowns or so and the bat felt a little better. I don't know if it is because I got my eye in more, or because it was just opening up! But Newbery 5 star bats are great value for money in terms of performance! I'm not sure what their grading is, but I think it is G3 willow, although you get the odd couple that look better than SPS grades!