I glanced over it when it came out - I always check out other epic spell systems, to see what other folks are doing - but mine was completely developed on my own. The spell modification tables are from the epic system, modified and expanded (they appeared in my first version), and the spell progressions are different too.
Your system looks more like Feanaro's - you figure up the Spellcraft DC, then convert to levels (your formula's off, BTW - it should be divide by 10 and add 7). Mine's a straight level-based system, where you take a base spell effect and tack on levels with metamagic and modifications.