Difference between msr606 and msr206?

I'm in the market for an MSR and was looking on the 206 as everyone says it's awsome. But I know a guy that uses the 606 for dumps and it works great.

So what is it that makes so much better? I mean it's like $100 difference in the price....

And further more, what exactly does it mean with "MSR206 compatable"?

I ran with a msr605 and not a 606. Hope it will do the trick, it stated that it were compatable with the msr206 so hopefully it will do the trick