For me, I wouldn't sharpen without an edge checker especially if you are changing discs to sharpen other blades (maybe one kid likes 1/2in and the other 3/8). I have found that there can be up to 6 clicks of alignment adjustment needed between discs. I am pretty picky when it comes to the edges being level thou. I like the Sparx Edge checker, I have had others but they wore a little grove in the aluminium where the blade touchs and it throws out the reading. The Sparx edge checker has a little piece of stainless steel that contacts the blade and doesn't wear. As for your alignment issue, I have only aligned mine once in two years (and I travel with the sharpener), I always go by the edge checker to move the disc if required.