They test to make sure that the PSUs actually are within the ATX12V standard...not all PSUs meet the standards that they claim. Poor voltage regulation and excessive ripple does cause premature wear/damage on PC components but 3% is not excessive. I would hesitate in comparing the reviews unless they were both conducted by the same site. Ripple would be more of a concern for me...how did the ripple compare.
Bottom line is that both are good quality PSUs made by a the same reputable mfr and either one will provide you years of quality power for your PC....choose whichever one you want.