I have well over 35K rounds through my PT92, a pre-decocker model. I replace the recoil spring every 8k rounds, b ut the locking block doesn't appear to have any imminent failures. They normally give you warning by showing rounding, chipping, or galling. The Beretta improved locking blocks, as mentioned, work in the Taurus as a drop in.
I have also put about 2K through my PT101, a .40 S&W, and have seen no abnormal wear on the locking block. The system is the same in either caliber, but the .40 S&W operates with a heavier bullet, and higher pressures than standard 9x19 rounds. ;D