5C and ER40 Collet Chucks, which is best?

https://youtu.be/pu7Y9lgC-b4

Channel Link:
youtube.com/channel/UCiACkN-H8fmDl_R0YZi1dMQ?sub_confirmation=1

ER40 Vs 5C collet Chucks. Why settle for one Collet Chuck when you can make 2?In a previous video I mounted an ER40 Collet Chuck onto my lathe, I have now built the same mount for a BISON 5C Collet Chuck.The video explores a comparison between the two with some real-world tests to see how they compare.So, which is best? Let’s find out.I'm not forming any conclusions about what the final accuracy of the chucks are, I'm just making observations and you can form your own conclusions.There are several lessons learned from this build that will cause me to completely rethink measurements in the shed.