Having worked at Atlassian before, I understand how important simple pricing can be. My personal (and probably biased opinion) is that this is a move in the wrong direction. It appears simpler on the surface, but the concept of a unit and understanding all the disclaimers associated with it make the pricing more complicated than before. If I have to read the faq to understand what I'm getting, it's too complicated IMHO. Also, it seems other features, like analytics retention, crawler, have moved into add-ons, which requires you to contact sales to find out how much you'll pay.
More granular pricing does provide more flexibility, but it also reduces predictability, which can be important especially in small to mid-sized businesses. I'm curious to understand how people feel about "usage pricing" vs. "tiered pricing" where you know exactly what you are paying each month? Which ones do you prefer? We are still finalising our own pricing, any feedback would be very much welcome.