Interesting-on the tru cut website it says it sharpens any brand of all the sizes listed but on the Nancy's Notions site it said it does not work on fiskars brand 60mm blades. I have a 60mm cutter but have only used the original blade so far, but after just a couple of small projects it's already got skipped areas. I'm debating whether to buy this sharpener or more blades. I'm leaning toward the sharpener. Is this the best brand?