I believe that most folks, once they start using one of the 300mm primes, whether the f/2.8 or f/4, realize soon thereafter that the focal length is not as limiting as they thought it would be. A few TC's (1.4x and 1.7x) and you've really got a workable system for opimal results.
I'm sure Thom's lemon was serviced at Nikon or exchanged.

Now, I do wonder if now with the D3's high ISO capabilities, whether or not that lens becomes more usable in lower light environments. I don't have one...so I guess I'll have to continue to wonder for a while and my next large lens purchase will be the 400 f/2.8 and I'll put that in front of getting the 24-70 again. If I can find a decent copy of a used 400 f/2.8, I'd probably go that route just given the cost factors.
Julio