Telephoto Options Help

You did Mike, but it has got a lot more use than the other lenses did combined even though I have the D3 and the Nikkor. Having the two lenses did present problems regarding redundancy (ie which lens do I take out today??) and replacing them with one solved that problem.

So are you saying that the 60-250 is good compromise over the longer Sigmas in combo with a 70-200, albeit that the AF is slow, or am I mis-reading that? Accepting the AF issue how does it compare optically to the Sigmas? I'd be happy to sacrifice AF speed and length for better IQ.

In that case go for the 60-250mm.

If I want fast AF with very good IQ then I take the Sigma 70-200mm and 100-300mm .. if I want the very best IQ and I'm not worried about the extra stop or AF speed then I will take the 60-250mm every time.

I went to a motorcross event at Mallory Park with togging friends of mine. I took my 170-500 and 70-300 cheapo Sigma as my longest lenses. Most of the time the 170-500 was far too long, even at 170mm. So in the end I used my 70-300 instead, with my 50-135 for some close to the track shots.
With hindsight, I think the DA* 60-250 would be perfect for 80% of the shots, but not having one of those, I coped with the different combos.

As an aside, one of my friends there, who does a lot of motorsport work with his Canon 1D mk3, and being a true blood canonite (nothing else will match etc etc) hired a Sigma 120-300 F2.8, used it hand held, and thought it perfect for motorsport.
So, if you are very flush with cash, wait for the mk2 120-300 from Sigma on the Pentax mount, which has been confirmed. If not, then either the 60-250 or the Sigma 70-200 will probably be more than suitable most of the time. Or, if you are looking at a budget lens, then even the 70-300 OS or 55-300 Pentax will be great, as you will be shooting at 1/125 F11 anyway.
Hope this helps.

Thanks for confirming my IQ assumptions re. the 60-250 Mike.

And thanks Offertonhatter for some further insight. Your findings pretty much concur with mine in terms of the anything longer than 300 being unnecessarily long most of the time, even at circuits more restrictive than Mallory which has to be one of the best in terms of trackside and infield access. (It's a great track to drive too despite it's seemingly boring looking layout!) As I mentioned at the start of the thread I have been very happy with the 55-300 which can produce some great results, I just want to try and move to the next level.

So all things considered I think I have whittled the choice down to the 60-250 if I can scrape the money together or the Da*200 prime, and keep the 55-300 for the longer stuff. Hopefully I'll get a chance to try some of the contenders at next month's FOI show.