I have reamers from all of them discussed and the Manson reamers I have cut the best but JGS is a close second. I've cut more chambers per reamer on the Clymers and several have 12-15 chambers and are still cutting good. One thing you'll notice with the older Clymers is they rarely cut on more than one or two flutes. On the JGS and Mansons they typically cut on 5 or 6 flutes (not always equally but they cut). PTG has been all over the map. We have some reamers that have only cut 2-3 chambers and will basically not cut after running it in over half way. A few have been back to PTG and they said they were fine but they still don't cut. I've heard from others that this is fairly common and have to be sharpened by some one else to fix the problem. A friend has a 6.5Saum reamer on order from PTG but I think my next reamer will be from JGS again. The last one took 5 weeks on a 6 week quote. The last PTG took 9 weeks on a 5-6 week quoted time. If Manson's times get that fast I would order from them in a heartbeat.