Ya, I'm actually considering trading my 238.5 for some more retail Prestige Pro's because I actually like the stiffness more. I hit just above center on the stringbed and the stiffness of the retail PP seems to work better for me, where as the 238.5 flutters too much.
I will try to run lead all the way up and down the sides and see if it it stretches the sweetspot and takes the flutter away. As it is, if it's polarized, the top of the stringbed is more stable and responsive, but the rest of the stringbed doesn't feel great. If it's depolarized, the center of the stringbed is better, but top of the stringbed flutters.
I had one TGK that didn't have this issue (a 238.4), but that's because when I got it it had a swing weight of 402 (static weight about 380), and it had a total of 8 layers of lead from 3 around to 9 o'clock. It's was amazingly solid and had good spin, but a little tough to handle after about 1-1.5 hours of heavy hitting.