I think having a lapping bar to check alignment at a minimum is an important step, even with quality rings and bases. If the rifle receiver is not perfectly built in unison with the rail, bases, base/ring combo etc. installed, there will be alignment issues, making the most precise built mounting solution pointless. If you properly bed to the receiver, then properly bed the scope in the rings, no lapping should be necessary. Another time is if you use the self aligning Burris signature rings, then nothing extra is necessary, the poly bushings self align. Personally I stress free bed the rail/base to the receiver, then lap the rings as needed, sometimes the lapping bar will only show that the rings are aligned, sometimes you will see they are not. On my next rifle I set up, I think I will bed the rail as standard, lightly lap the rings to ensure no stress points and that there is proper alignment, then I will bed the scope into the rings.