The goal is to provide a much easier way to read mailbox, but if you maintain a 0 mailbox balance, this may not be the mail client you need.
The display format of your emails is what's been changed. It's been made to look like a conversation list. I personally don't see anything more from this mail client than what you find in Gmail, CloudMagic, Boxer etc..
I do like the choices of various colored themes, it should accommodate everyone style and preference.
I'd give a whirl if you're in the market to get something that will make more sense of your emails then you would.
You may be interested to know that the client is FREE.