I just want to hear an opinion from the forum readers, before I decided to buy which camera. Currently I am looking to buy the 1D bodies, I shoot birds, wildlife & landscape and I am not a wedding photographer.
I like the 1D4 because it offers good AF, reasonable ISO and autofocus available at f/8 and I don't mind getting a used body (it's cheaper). On the other hand the 1DX a new AF (autofocus only up to f/5.6) and ok I admit I like the new feature such as built in HDR for my landscape and multiple exposure (something interesting), but it's pricey.
So, in your opinion which one is better to get the 1DX or 1D4?
Well it depends. Anything the 1D4 can do, the 1DX does better. However, for price, if you are shooting sports in enough light, go with the 1D4. If you do low-light sports/indoor sports, and weddings for instance, you'd get the 1DX or 5D3. If you love the built-in HDR and ME modes, actually the 5D3 is better. The 5D3 actually does very well in good light with AF and action/sports. If you don't need that, and want only speed and fps, and AF-point linked spot metering, get the 1D4. It's a tough choice for you. Of course, if you spent the $6799 on a 1DX, seeing as how it's good for at least 400k actuations, it'd be a good, lifetime investment that you would never regret. The 1DX, 1D4, and 5D3 are all fantastic. Whichever you buy, the 1DX or 1D4, you'll be happy. Be careful though about low-light with the 1D4, noise starts showing up pretty thick at ISO 6400.