I have the '06 S "Special Edition" model.
I bought it used with around 30k miles and at 194k I've not had one mechanical issue.
The single cd player in the car started eating cds and can't be used and the 6 disc Rockford Fosgate changer likes to eat them as well...so I don't use them. I think the entire Rockford system is junk and just a cheap version of their normal products.
The backseat is not meant for adults at all, it is miserable for hauling adult passengers or anyone over about 5'4" tall.
I used my Sentra to commute 3 hrs a day for work and it never let me sit and never broke down.
Keep up with maintenance and it's a good car.