Not all are discontinued
the three limiteds (31mm, 43mm and 77mm) are still being produced, as, I believe, the 50mm F1.4, but this is still to be confirmed (one place said it was stopped being made in 2004, yet another says still made albeit in smaller numbers)
the two macros, the 50 and 100, were called FA, but now DFA. They are for all intents and purposes the same lens but with very minor adjustments.

Its just a shame that the 35mm F2 is no longer being made, having stopped earlier this year (so I believe)

Nice to see the prices coming down, getting closer for the K-7 me thinks.

Mind you I did pay £800 for my *istDS back in december 2004!

I very nearly got this lens too from the local Curry's for the same price (mind you currys and PC world are the same anyway). However a visit to a local classic camera place had an immaculate Sigma 105mm EX macro for £100 less. So in the end it was a no brainer. However if the classic camera place did not have it, then a trip to curry's would have been forthcoming.

Thats the one thing I forgot to mention, The Bigma, although more than the 150-500 or 170-500, is still a LOT less than long Nikkors or Canon L's
So for what you get, it is a bargain (if you can call £1100 a bargain) For a long CaniKon prime, you are talking £5-£6K?
So, yes the Bigma is cheap and great, but is it worth more than the "lesser" models in the Sigma range... Like I said in an earlier post, it depends on what you want to use it for.

True Mike, however the Canon 100-400 got walloped by the 120-400 and 150-500 in the PP test. I have a could of friends with the 100-400, and although good, they say it is not the best. They always complain about the lack of decent long tele-zooms in Canons range. In fact one guy hired the 120-300 F2.8 Sigma instead and found it great.
The big down side of that canon, is the push/pull, pumping dust onto the sensor.....
Canon's L primes on the other hand.....£££££££ but exceptional (why can't Pentax produce Fast long primes...mutter mutter)

16-45mm Great lens!
However, in certain cirmstances (studio work for example) not "quite" as good as my Sigma 24-70mm EX F2.8 sharpness wise.

I have also tried the Tamron 17-50mm F2.8 and it is "just" sharper, and has the advantage of F2.8.

But, and here it comes....

My Sigma cost £300 4 years ago, the mk2 is £700!
The Tamron is £349
My 16-45? £180 back in Feb. Even now only around £230. Why? it is being superceded by the DA 17-70 SDM....

Bargain!

Buy one now, while you still can, you won't be disappointed.

sounds like the grease is solidifying.

Best to take it to a classic camera shop, and get them to service the lens. It will cost but will be worth it. It will be like a new lens.

Not got it, but I have tried the Tamron, and it is excellent. Personally, go for the Tamron (its better even than my 16-45mm, and that is saying something) I am saving up!

I have the Sigma 70-300mm non APO lens, and whilst good, and a bargain at the time of £89, it is not the most reliable lens I have by any means. It is now causing issues with whatever body I put on it. mainly not talking to that body, and being troublesome when I go into Fn menus (flashing off not letting me do changes etc ) but no all the time. When it works then it is good, when not, it is a pain!
Personally go for the Tamron instead, or the 55-300 DA (but this does not give you the option to put the lens on film bodies, where the Sigma and Tamron does.

If you can stretch your budget, go for the 120-400mm instead. It is getting great reviews, winning group tests (Practical Photography) and reasonably priced (less than £600)
Personally, I am going to dump the 70-300 and maybe sell the 170-500 to buy the 120-400 instead.

I have the 170-500 model, and it is not the sharpest, and does lack some contrast, even in good light. However, It is not too bad, and some small amount of unsharp mask and a tweaking the curves in PS, brings images created back to life. I have a couple of friends with the bigma on Canon and Nikon mounts, and it is better optically than the 170-500. They do say that beyond 450mm it does get soft though. Is it worth more than the 170-500? well it depends on what you want. If you are solely doing long end shots, then probably no, but I was at Mallory Park the other week and using the 170-500, and there were times when it not go wide enough, so I was having to change lenses. So for me, It is worth it, as you get that useful wide length of 50-170, that my current lens does not give.
So, horses for courses really. If you are just going to do birds, then a 170-500 or its successor the 150-500 makes more sense. However, if you want a good general purpose tele-zoom, then the bigma is the one. Just don't expect Nikkor, L Lens or DA* super-sharp images or faster AF.
Its very very good, but not the ultimate.