This was my 370z before I just sold it a couple of weeks ago. I bought it brand new when they first came out in 2009 while I was deployed to Iraq and stationed in Germany. Not overly popular brand in Germany so you never saw many. It had been on the autobahn, where I hit 155mph according to speedo. Went through winters in Germany and Maryland. It was fully loaded and went on 4 trips (4,000 miles round trip) from Fort Bliss to Maryland and back with no problems at all. I kept it stock until 3 years ago and went mod crazy. I did all the bolt-ons with a Uprev tune @329whip. Slightly nostalgic details as I do miss that car sometimes.
The only major problem I had was the CSC and it happened at 7,000 miles. I had to have it replaced at a German Nissan dealership under warranty of course. Even though it was an American Spec car I bought through a US military contracted dealership. Once I had the CSC replaced I never had it go out ever again and I sold the car with 65,000 miles on it.
I would probably consider myself lucky because I do know some people in the Z community that had to replace it more than once. They have to drop the transmission which is mostly why it is so expensive to replace. If you get one there are aftermarket solutions that delete the CSC and replace it. Runs about $1800 ish. If the stock CSC goes out you will have to be towed!
Top Gear did a head to head when the 135i came out you could probably find on youtube. It's not practical. You can't get a ton of power unless you Turbo it. I'd recommend it as others mentioned diff, oil cooler, brakes, and CSC are a must.