Started out with PTG reamers years ago then got my first JGS and promptly replaced all my PTG with quality reamers and I have been reluctant to try others just cause the JGS is such an excellent tool but I chambered up a 7 Sherman MAX to give the Manson a try and was very, very happy!! The little keeper ring was a little annoying BUT with the coolant groove fully exposed I think I had better coolant flow on the Manson than with the JGS high flow bushing, stopped a couple times to check and had complete chip evacuation the whole chamber which just makes better and easier chambering. It did like a little slower feed but still just dropped in like butter, surface finish was outstanding and it cut a spec chamber and just ran smoooooth!! HUGE thumbs up on the Manson reamers for both quality and pricing!!!