It's new, it has a warranty, technology moves on constantly so everything will be machined and built to a better standard. And it's more powerful.Oh, and on top of all that, it'll have that new car smell. I'd buy it
On the downside, I don't think the Nismo has any of the luxuries like heated seats or air con (feel free to correct me on that) that the non Nismo versions have (I do like heated seats)
That's my ten pence worth