I have actually come to like the gas cap. It doesnt leak at all where the old ones could once they got older.The BR600 is the brute of Stihl's lineup. I have one and I like everything about it except for the gas cap.
BTW, if you don't like mixing oil and gas (I think that's what you were trying to say above) then you won't like anything Stihl has. Their 4 Mix engines use the same gas/oil mix as their 2 stroke engines.