George83,
I use the Holland and Gre-Tan assemblies for all of my custom extreme range rifles for my customers. Never had anything to complain about either of these two.
I am sure the others are fine to but I use these two and thats it because they have never gien a reason to change.
Just replaced the assembly in my personal 2000 yard rifle with a Gre-Tan assemply.
Good Shooting!!!
Kirby Allen(50)