Important ?, yes! To put in a nutshell what I have learned by hands on ,OK, here goes: GM TEC ,yeah , I know , I 'm a ,whatever. Side by side comparisons , over and over , let this one be first , then that one, follow up with the next one, ad naseum. To modify this stance a smidgen I will say that after the gm tec failed to produce any further fouling the Barnes CR 10 would do a little bit , not much. Does anyone have any idea how much money GM spent to bring this product to the market place? Yes , I know that it was not developed for shooters , but , hey take a look at Butches Bore Shine( same ingredients). I have bought and tried them all ,my methods are not perfect but there is one thing sure , results are so far within a "corral " of results that I don't need further testing . I gave away the losers . BTW, thanks to all of you here, my shooting is better now than it was 30 yrs. ago even though my vision is not as good as then. Jim B.