yup, agree with mb - it's a must with 70-200

Best choice, TC-17E is a must have accessory if you have 70-200.

Thanks Everyone

After reading your comments, seeing some sample images and doing a little extra research I decided to go for the TC-17E option. Seems to be the best bang for the buck for my needs.

With TC-17E you will get smallest f stop around f/37 that could be useful sometimes but 70-200 is at it very worst regarding sharpness at 200 and smallest f stop when using TC.
300mm f/2.8 ED-IF AF-S VR is much better at 300 than 70-200 + TC, it is probably better then anything else at 300 except 200-400 that is about the same price as 300 but is a bit more versatile and bigger and makes TC unneeded. They are both much bigger then 70-200.

I wonder how do you want to compare something that costs 5000$ like 300 and 200-400 to 400$ TC?
On the other hand 70-300 works surprisingly well on D700, it is lighter and smaller then 70-200 alone, and you will not need TC or 70-200 at all most of the times.

I guess it's all relative. To me 9cm is slight when lenses are this big.

This guy frequently hand hold his 600mm Canon with image stabilization and gets these kinds of shots:
http://www.juzaphoto.com/eng/galleries/fauna-bird_wildlife_texel_netherlands.htm

Now a 600mmF4.0 is a big enough difference and despite what some may believe, it is possible to hand hold a 300mm2.8 as it's a bit smaller.

gentoo - 9cm in length is not a "slightly longer" lens - 300/2.8vr is almost 33% shorter :) - the link You are referring shows the old version on AF-S 300 2.8 (w/o VR)

This is for DX as well. Most birder use DX for their birding shoots and 300 is minimum. 400 is min for FX.

Gentoo - When you say 300mm is the minimum, are you talking DX or FX?

I ask only out of curiosity cecause I don't shoot wild-life (unless you count my dog).

We've had 10 consecutive days of 100 degree + tempretures and its driving all the wildlife (dear where I live) into the irrigated urban gardens to feed. Could make for some cool shots.

The 70-300 is good within it's limits. Like almost all consumer level lenses, it doesn't like being pushed to it's limits. This is why I eventually got a 300 prime as it performs much better being a fixed FL. I would guess that if you're using super teles, you're shooting them mostly at their maximum focal lengths. You still haven't told us what you're doing but if it's wildlife and especially birds, primes are the way to go and pro zooms like the 200-400 are good alternatives and perform just about as well. For wildlife, I would encourage you to try to get beyond 300mm as this is the MINIMUM for wildlife shooting.

It also depends on where you are when you're shooting. From my experience and from talking to other birders from all over the world, your needs will vary with location. In most of Europe 400mm is said to be the necessary minimum. Apertures of 2.8 to 4.0 should be what's aimed for. In my region, I can get away with 4.0 or 5.6 most of the time as well as 300mm. Again, this is from a birding point of view so this may or may not apply to you.

As adamz mentioned, a tripod would be necessary for most people with the 300 prime 2.8.

"This, unfortunately, I can't say about the 200-400/f4 - it's a great lens, but if You stay in one location for a longer period of time, as the mobility with this lens is limited - it's simply too long and if You travel by plane You might have problems with getting it onboard in some airlines."

The 200-400 is only slightly longer than the 300F2.8:

http://www.hickingbotham.com/reviews/nikon300200400.htm

Normally, I'd say go for some longer glass like the Nikon 70-300 (which costs the same as the TC-17. To me though, you have to ask yourself if you want to carry around that much glass. a 70-200 and a 70-300 (or the more expensive primes) is a lot of bulk to tote around. Especially if you've got a 24-70 and a wide angle thrown in. If you've already got the 70-200, save your back the trouble and go with the TC instead (assuming 340mm is long enough for you).

bmxdad - IMHO it feels solid, I'm using it on d200, d90 and f100 and don't have any problems with it

as for glass, bigger glass is always a better solution, but also always more (much more) expensive one, gentoo mentioned 300/4AFS + TC14, it's a considerable combination, but You get f5.6@420mm and all this without VR, which means tripod support highly recommended. I would prefere 300/2.8 + any TC as You get great combination. I've played once with this lens + TC17 and found the results are really awesome and You still have mobility and VR support. This, unfortunately, I can't say about the 200-400/f4 - it's a great lens, but if You stay in one location for a longer period of time, as the mobility with this lens is limited - it's simply too long and if You travel by plane You might have problems with getting it onboard in some airlines.

so summing up, IMHO the perfect mobility kit would be:
70-200/2.8 vr as a zoom
300/2.8 vr prime
2xTC-17
two bodies, one with 70-200/2.8+1.7 [119-320@f4.8] for zooming, and one with 300/2.8+1.7 [510@4.8]

The TC17E also works well with the 300 2.8 and the 200-400 F4. I know this because birders generally don't use the 70-200.

Having said that, I agree with you as I've said before that longer FL are better if indeed this is the type of photography is what is being done.

The TC17E was designed in conjuction with the 70-200 VR. There is no other Lens + TC combination that works better together. Having said that . A long prime will do better. Why are you needing longer? IS theer a specific reason. If there is, then it may be better to get a specific lens for it.

Being a fellow wildlife shooter ( I assume you are by your needs), I'd say, if you can afford it, go with the bigger glass. Any birder will tell you. Don't know if birds are your thing but if they are, big glass is almost always preferred. If you can afford that lens you can get the 1.4 or 1.7 TC for it and really increase your reach. Once you start trying to shoot Sandpipers way out on mudflats or ducks (not the domestic or feral ones) that stay way out on lakes, you will put that combo to a lot of use. I would say especially since you have a D700 as the advice I gave you is given even for those of us with the 1.5 DX crop factor.

You can also go the cheaper route and get the 300mmF4. A 1.4 TC will give you 420mm5.6. But with the 300mm2.8 you could use a 2xTC and get 600mm5.6.

Hi Adamz

Does the 70-200 2.8/TC 17 fell solid when in use. I would also like to increase my reach of my 70-200 VR while maintaining AF, Sharpness and relative low F stop

Thanks Pete

NSX - full AF with 2.8 or faster lenses, and I don't see a big difference with and w/o TC mounted

Nikon TC-xxE does allow auto focus, and manual override is possible with lens that supports it (70-200 does).

Do the teleconverters allow for autofocus, or do they require manual focusing afterwards?

I am getting one also with my 70-200VR and have only seen positive things about the TC-17E tele-converter.

Here is a link to someone using them: http://dslr-video.com/blogmag/?p=199

I think this is by far one of the best tele-converter you can get, maybe the only downside is that it will only work with Nikon 2.8 tele lenses. Yes you can modify it to be used with other lenses.

Pete

300/2.8 + TC17 :) - as for TC17 + 70-200/2.8 it's a great combination, I'm using it for 90% of my shots, wide open and can't say anything bad about both IQ and AF speed (LINK)

Hi Folks:

My longest focal length is 200mm (70-200 F2.8 VR) but occasionally find myself in need of more reach. I am considering the TC-17E Tele-convertor vs bigger glass such as the 300 F2.8. I use a D700. Any thoughts?