I held off saying this, but last month I purchased a used D3X from KEH with 364 clicks on the shutter. (KEH rated it LN-, but it looks Mint- to me.) I've been looking to upgrade to a full-frame Nikon with double the megapixels of my D200. (I already have the full-frame zooms from a 14mm to 200mm range, and one MF macro.) So far, I haven't had the need for high ISO (400 to 800+) capability, and I like the results from the D3S and the D3X bodies that I've rented and used.
Question: The D3X manual states the camera will handle up to an 8gB memory card; there's also a firmware upgrade for 64gB memory cards. Reading the manual as to memory card capacity with the various camera settings, this upgrade looks to be a good idea. From your experiences, is it absolutely necessary?