the real difference between PSI and Beall is the knurled collet nut on the PSI. If you do a lot of close work or sanding near the collet, the Beall is knuckle friendly and your hand would bounce off. The PSI you have to keep away from the collet nut. Really depends on what you are making and how close you push your safety limits.
OH I HEAR THAT! Disclaimer, I'm not saying one should pick up bad habbits. I'm just saying in the 2 years of using it, I've hit the collet nut 3 times, luckily the Beall is smooth so no blood. However, other PSI owners have noted BLOOD!
Beall twice the quality that that of PSI.
Even Craft supplies Apprentice has less run out that PSI.
Go Beall and don't look back.