Yea that's a great number but the variance in heads up LHE is huge. I'd say you'd have to play 400,000 hands to get a real solid indicator of your win rate. Of course after that many hands of playing you'd have improved and drastically changed your play so much it'd be different.
This post isn't getting to the point which is, 7 BB/100 is great but probably not sustainable against competetant opponents. It's gonna take a long long long time to know just how good you are, but there's only one way to find out, and that's to keep on keeping on!
Godd Luck.[/u]