Just to play devil's advocat for some fun...
Is a larger LCD really that important
If you have to ask, for you perhaps no, but for someone that wears strong glasses, and no longer needs to see distorted images in the viewfinder or press their glasses up against it, that is a recepie for a happy camper.
is sensor cleaning really that important
I personally do not think any of them work well anyways... but the next time you see a spec on your pics and have to spend money and time cleaning it when a press of a button may do it for you for free and immediately... well it has just paid for itself. I feel this is more one of those "features" that is neither good nor bad.
who cares about live previews Id rather look through my viewfinder
That is you, bue any photojournalist that needs to shoot above his head will be thankfully using this feature. I wish my D200 had this feature, I often needed it to get that pic in a parade blocked by people or obstacles in front of me that were avoidable by shooting overhead. On the D200, this is impossible to do reliably... its one big guess.
and a 51 point autofcus seems overkill, my D200 has 11 and thats enought for me.
A quote from a D200 user that had a chance to use a D300 for a day, thanks to Nikon: "I did not think the 51 point autofocus was a big improvement... but in fact it made my 11 point system on the D200 feel lethargic and about as fast in comparison as my D200 is to my 1990 P&S..."
There is a lot more to the 51 point setup than just having 51 points. It is focus accuracy as well as a blinding speed difference to acheive focus. If you have ever taken a pic of anything that moves, you would appreciate this.
Yeah the D300 may shoot 8FPS which is nice but I dont think any of the things listed would put it in the same category as the D3
It is not in the same class... else it would be a lot more expensive, or the D3 a lot cheaper. The D3 is a professional level camera for people that KNOW how to take advantage of it.
I still feel the D300 is more inline with the D200, better but more in line.
The D300 is the evolution of the Dx00 line based on the improvements it has over the D200, thats true... but in the same breath, it easily outperforms the D2x line quite handily in several areas, it is that much better.
The D3 is very much a revolutionary camera. It has gone over and above any improvements not just over a D2x, but it has set new industry standards in the process. There are so many changes and improvements that one cannot compare the 2 quite so easily anymore.
Consider the D300 as the new pro-sumer line or top end dSLR for the masses.
The D3 is for professionals and it deserves the best glass out there and just like a highly tuned race car, it demands an experienced hand to get the most out of it.
Can anyone use a D3? Sure, but the effect would be similar to putting a grandmother into a formula race car... not very spectacular... lol.
Concerning the flash... like it or not, there are times that you MUST use one to get the shot. Having this camera is NOT a guarantee that you no longer need one, it does mean that your lower light shots come out a lot cleaner and with less digital artifacts. Oh... the D3 comes with NO flash at all, not even to use as a commander. That I think is a mistake, one that doesn't exist on the D200 or D300... which both have an integrated flash that can be used as a trigger up to 3 compeltely different sets of off-camera strobes for the Nikon CLS system. As to how effective CLS is... well, thats a topic for another thread.
My next camera shall be of the FX line (D3 or D4), and I get to sell my D200 and all the lenses but two becuase they are in the DX format.