I suspect your Nikkor will be a better lens. I have the slightly older version of the Sigma lens and the images are disappointingly soft at mid-full zoom. Always worth reading reviews of lenses before purchase. It was cheap when I bought it, but in the long run I wish I'd paid more and got a sharper lens.

Yes, fits all Nikon F mount

You can buy a month's prime membership for £7.99 if you really wanted this.

that's the lower spec model without APO selling for £90 at Currys, this model sells for £150 at Currys http://www.currys.co.uk/gbuk/cameras-and-camcorders/photography-accessories/lenses/sigma-70-300-mm-f-4-5-6-dg-apo-telephoto-zoom-lens-with-macro-for-nikon-20965701-pdt.html#srcid=11026

In my opinion APO is a must.

Here's some info in the mean time:

http://www.imaging-resource.com/lenses/sigma/70-300mm-f4-5.6-dg-macro-apo/review/

https://m.dpreview.com/products/sigma/lenses/sigma_70-300_4-5p6_apo

​Yes absolutely love it. Have the Canon mount & it's been on a 350d & 1000d its a good solid lens, it has its flaws the obvious being 300mm with no IS but tripod mount it with fast exposures & it does a good job.

Absolutely brilliant for wildlife shots, brilliant flexibility due to range covered. I paid £150 in 2006 or so I think & pleased with it still in use now.

Where else can you get 70-300mm for under a ton? It's a real no brainer even if you're unsure if you need the range it covers

​I owned one for 2 years. Bought it for some ridiculously cheap price on eBay. Seller had a dozen. Wish I'd bought the lot.

Loved the lens. It had a few limitations but as long as you accept that, you'll be happy with it.

correct, I have the OS stabilized version brand new unused, I never bought the camera itself if anybody wants a part exchange or even to buy it.