I need to buy some new steb centers. I have been using the PSI brand for 6-7 years, but the are showing some marks mid-way of the taper. I have been cleaning them up with 400 grit paper with oil. They are inexpensive and have worked well. Looking there is Woodriver slightly higher and then Sorby 3X more than PSI. The Sorby's have a relief mid-way of the taper. What do you use or recommend?