Zero-fee = Fee-free = Feeless = Bytemaster's original idea -> Not suitable name for abit's implementation.
Balance based fees -> Also misleading, because fees are not going to change based on balance. Fees will be same for everybody, but depending on how much your balance is, you have credits that you can use to pay the fees.
Come on people, this shouldn't be so hard. Only scammers and pump'n'dumpers will market their products with vague and misleading names and descriptions.
This is what happens if we choose misleading name for feature:
"Oh, cool, you have zerofee transactions! That's best thing ever! I'm going to start using Bitshares and tell all my friends about it!"
"Uhh... Wait a minute... There are lots of fees here... This is not a zerofee system..."
"So you lied to me! Bitshares must be a scam project. Fuck you guys, I'm going to tell everybody that Bitshares sucks and it should be avoided like a plague."
Never ever lie to your customers. It will backfire every time.