>I want >to expand to full frame and was about ready to pull the >trigger on a D800 when the opportunity for a slightly used D3x >came to me. The D3x is roughly a thousand dollars more than >the 800 and I guess my dilemma is: am I really missing out on >a lot other than megapixels, I realize the 800 has a >technology advantage but many of my professional friends are >dedicated to their 3x's, and having large hands the 3x fits >better and has a much more secure feel.
For the kind of work you do (and plenty of other things too!), the D3x is a superb camera. Your pro friends have stuck with the D3x because they spent a lot of money on it in the first place, and because the camera produces superb photos day in and day out. The D3x just works and works and works and works and won't let you down. To this day, its technical image quality is really second to none.
The D3x is a very high megapixel camera - 24.5 mp to be exact. That's a lot of resolution. You'll be very happy with the results. I don't really think the D800 has anything to offer for the kind of work you tend to do - not compared to the D3x. The differences between the two cameras, for the kind of work you do, I think exist largely on paper. The D3x remains a top-of-the-line pro body for Nikon.