My preferred set of dies
Lee Collet
Redding Body Die
Competition Seater with micrometer (Redding, RCBS, Forster)
Lee Factory Crimp Die
The Lee Collet sizes the neck by squeezing the neck brass between the collets and a steel mandrel. Once the brass has been pressed onto the mandrel, it does not matter how much more pressure you put on the collets, the neck is not going to be sized any more. IOW the steel mandrel can not be compressed
Lee says the amount of pressure is at least 25 pounds
https://leeprecision.com/cgi-data/instruct/RM3512.pdf
Don't know where but I have read that 25 pounds of force on the handle translates to approx. 600 pounds of force on the case. If your mandrel is .002" smaller than caliber then it won't matter how much further down you turn the die or how much force you exert with cam-over, it will not size the inside of the neck any smaller.
To make it easier for me to put approx. 25+ pounds of downward force on the handle I have found it easier to just adjust the lock nut up to the top of the threads which puts the press handle at it's most horizontal
There are other factors that influence the final dimensions the die will size your neck brass to. Most important is hardness. Springback for brass is in the opposite direction to the applied force and the more hardness either from firing or sizing the more springback you will get. Since the collets are pressing the brass inward onto the mandrel the springback will be outward, IOW the harder your neck brass the larger the inside diameter will be. So annealing will keep your inside diameter smallest.
Sizing will increase hardness also. With a regular die with expander the neck is sized twice with each operation, once to a smaller dimension and then the expander will size the ID larger.
Other advantages:
No lube inside the neck
Mandrel floats so it doesn't mess up the concentricity your chamber has developed on fired cases
You can leave a section of the neck at the shoulder junction unsized by using a washer on top of the shell holder
Better concentricity, at least in my tests
YMMV