I was always under the impression that the top end Nikon / Canons were bullet proof?
Or is it a case of the more extreme environment you work in which cause them to not last as long?
The cameras are fine, better than fine, in fact. Just that because of the rapid advances in digital technology, we're forced to keep upgrading before they actually wear out in order to keep abreast of the competition.
Now we're finally seeing those tech-advances plateau a bit - there won't be such a need to upgrade as rapidly as previously.
With a D3, D3s and D3x I have all bases covered - fast, high-iso bodies for general and press work and a slower but high-IQ body for studio.
Remember that Nikon initially introduced a new pro camera every 12-15 years in the days of film.
We were only up to F5 by the time the D1 came out.
Now we're already up to D3x, which if you took each DSLR Pro-camera individually would be like a D5 or D6 (in old money) - in 9 year period...
Incidentally the D2x bodies I used three and four years ago are still in use by a tier-2 photographer here in Germany...
...and I'm still using Nikkor AF-lenses which I've owned for 15 years...
And film cameras don't age in the same way - my F5 is still as cutting-edge as when it was introduced in 1996 - the only limitations are those that the recording-medium (film) imposes...as for the F6 which came out in 2004...who bought those? You want a smaller film-camera? Buy an F3 instead...