presuming the rifle receiver mounting holes are properly aligned and you use precisely made base/rings, I think you will find the Picatinny setup to be pretty much dead on for windage. I set up a Rem 700 w/Badger base and rings (Picatinny style) and used less than 1 MOA windage from optical center to get lined up at 600y.
Once you get zeroed, you should get comfortable twisting the knobs. That's why they exist. [img]images/icons/smile.gif[/img]
You should also be able to remove your scope, remount it, and have very little shift in zero.
it's not about need in the USA -- it's about WANT