I'm a first time Z owner, never been a car enthusiast in the slightest, so feel free to trash my opinions if you like.
When I first saw pictures of the 370Z, I figured the car would be small, but in actually, proportionally to my size, the car is pretty big, well more like wide and thick. lol
It wasn't a tiny car. It's bigger than some slightly older cars, so don't underestimate the size. I did.
As far as blind spots, it's not too bad. Make full use of the windows. Driver side, you can pretty much look out and back through the driver side window and see any car that is in your blind spot.
The passenger side is a bit tricky. I try to look ahead of time in the direction of passenger side to see what will be there as I drive by. Looking out the back window helps to see if anyone is coming up on your rear so you can avoid them.
I've had to use the trunk once for groceries, and it held alot of bags nicely. Even though I won't be doing that again.
Before finally deciding on the Z, I was looking at the RX8, Mustang, and Camaro. One of the factors that made me select the Z was it's nicer interior.