I absolutely love my one piece, bottom mount, system by Deadnutz.... (actually 3 piece...the cradle, and two cap rings) the "cradle" if you will is dimensionally CNCd from one piece of stock.... thus the base "rings" cannot EVER deviate position from one another...
The only drawback is how you set up your rifle for eye relief... these mounts are oriented to the mounting holes already drilled into the top of your receiver.... thus the amount your scope can travel back and forth on "top" of the rifle to find that sweet spot for your cheek weld is somewhat limited in distance.
After numerous falls, slips and crashes on snow swept mounaintsides for days...my scope was DEADNUTZ despite.