mtf10 and 30 are pretty easy for lenses this long. I'm pretty sure Canon's MTF charts show up to 50 (the faint dashed lines). At 10 and 30 Canon's superteles all look very close to this.
i really don't know how to read MTF charts either... but I saw this one and definitely noticed a difference from other lenses.
anyone have any more insight in to what this actually means?