[ioszhka]

They're very different lenses. From what I recall Tokina 80-200/2.8 was quite heavy, but very well built and solid feeling. The 70-300VR is a lot smaller, lighter, has quite a bit more plastic ans isn't quite as well built. But we're talking about a constant f/2.8 telephoto zoom as compared to a consumer zoom, so the weight and build differences are to be expected.

I can't really compare AF speed as the only time I shot with the 80-200 was on Pentax (a K-7, I think). The 70-300VR was shot on my D700. Needless to say the AF on the 70-300 was significantly better than the 80-200. How much of that was the lens and how much was the body? Probably a lot of both. Without trying an 80-200 on a Nikon I couldn't say for sure, but I have a feeling the AF-S 70-300 would be quicker in terms of AF than the 80-200 even on the same body.

IQ, again, hard to say from the limited amount I shot either lens. If you stop the 80-200 down to the same apertures you'd be at with the 70-300, it wouldn't surprise me if the IQ was better. That said, I think the IQ of the 70-300 is quite good for the price.

I guess overall if I was choosing between the two lenses, I would only select the 80-200/2.8 if you know you needed/wanted the ability to shoot a fair amount between f/2.8 and f/4. Otherwise, I'd probably go for the lighter, faster AF 70-300VR with more range over the 80-200.

Thank you for the comprehensive answer. That was really helpful.

[elho_cid]

One year ago I compared the AF speed with slot driven lenses with a friend using Nikon D7000. He also has a D300.
He was surprised to see that K-5 drives comparable lenses faster than Nikon, it probably has stronger in body AF motor. Adding the SR to the equation, it makes sense to try getting these or similar lenses in K-mount...

At that time we compared FA*85 against some 85mm Nikkor. I'm not sure to what extent can this finding be generalized, but I'm curious what are the experience of others.

[ioszhka]

One year ago I compared the AF speed with slot driven lenses with a friend using Nikon D7000. He also has a D300.
He was surprised to see that K-5 drives comparable lenses faster than Nikon, it probably has stronger in body AF motor. Adding the SR to the equation, it makes sense to try getting these or similar lenses in K-mount...

I do not doubt your results and I do find them interesting, but let's put it this way: If I would sell my D300 and get a K-5 then I will not have enough money for all the three lenses. I know that the K-5 is a very good camera, I've read almost all the extensive reviews on it. I really love Pentax equipment, but cost and availability play a big part here, and with Pentax both are kind of hard to meet.
My first dSLR was a Pentax K100D and after that I had a Sigma SD14, Pentax k-r and this Nikon D300, and only the k-r felt almost as nice as the K100D. I'm still looking for a camera that was such a joy to use. But for now, it'll have to be the D300. Hopefully, in the future, I will have enough cash to buy a good set of lenses and a good Pentax body (preferably the K-5 or it's successor).

[dgaies]

One year ago I compared the AF speed with slot driven lenses with a friend using Nikon D7000. He also has a D300.
He was surprised to see that K-5 drives comparable lenses faster than Nikon, it probably has stronger in body AF motor. Adding the SR to the equation, it makes sense to try getting these or similar lenses in K-mount...

At that time we compared FA*85 against some 85mm Nikkor. I'm not sure to what extent can this finding be generalized, but I'm curious what are the experience of others.

The in-body motor of the K-5 is very fast/powerful, and could very easily be on par with the D7000 and D300 in terms of pure driving speed. However, I still contend that the D300 is superior in terms of overall AF performance, which of course will depend somewhat on how you're using the camera. I also agree that the FA*85 focuses extremely fast on the K-5. I've used the FA*85 on the K-5 as well as the 85/1.4D and 85/1.4G on the D700, and there's no question the FA*85 is a very fast focusing lens. Keep in mind, it is probably the second fastest focusing K-mount lens I've used (the DA40 being the fastest). At the same time, the 85/1.4D and 85/1.4G are certainly on the slow side as Nikon lenses go.

I also agree that adding SR into the equation does make a somewhat compelling case for switching to Pentax. To be honest, the in-body SR system is what attracted me to Pentax 6 years ago when the K10D came out. However, as the OP points out in the post above, if switching from a D300 to a K-5 leaves him without a budget to buy the lenses he wants (which will no doubt be more expensive in K-mount as compared to F-mount), then it's not really an option.