I purchased my 2014 370z with a set of Megan Racing Springs already installed. I was happy with the drop the Megan's offered, and never found them to be overly harsh. My biggest issue was encountered while pushing the car hard. The outside front tire would "chatter" in a sensation like it was bouncing up and down. This was exacerbated whenever I encountered a bump or elevation change mid corner.
I decide to switch to the Tein S Techs, and have been 100% pleasantly surprised all around. The overall ride is smoother but firmer. It's a hard sensation to describe, but essentially there are no longer miniature upsets of the cars suspension over rapid bumps. I've also found that body roll has reduced a notable amount. In addition to these improvements, even while pushing extremely hard, the car is planted and communicative. No more outside tire chatter or mid corner upsets. I can tell more of what the front is doing than I thought possible.
Actual drop height in the front is in the range of 1.2-1.4 inches, rear is 1-1.2 inches. I'm not being 100% accurate, as I am unsure if and how far the springs will settle over the next few months.