I'm on my third 370 now - first was a GT Ultimate (2009) (No mods), second was a 40th Anniversary Edition (2010) (Aftermarket CBE) and now the current Nismo (Mods listed below). I don't get to drive as much as I'd like but I reckon I've covered about 30,000 miles without encountering a significant problem. The one issue common to all three cars has been the slightly irritating boot spring problem.
Having been hanging around this forum for a good few years, my impression is that they're generally very reliable cars.