I have one and I swear it dulled the blade. IMHO, not worth the money. My next strategy when I need new blades is try the ones you can buy by the meg off Ebay. Can't hurt to try. Also Wawak's (no affil) sometimes has great prices on real Olfa blades.
I'm with you on trying to sharpen. Blades have gotten REALLY expensive. I remember when you could get a 10-pack really reasonably, now the 5-packs are outrageous and the 10-packs are non-existent.