I have read a lot of reviews saying Sigma just as good a Nikon lenses what are your thoughts?

JComer--If you search on the site for specific reviews I've done you can see my thoughts. Both Nikon & Sigma make lenses from $100 to $10000 and I think that in at least several lens categories (12-24, 24-70, 120-400) Sigma makes lenses that are highly competitive with Nikon and often much less expensive.

In other categories Nikon has unique offerings that can't be touched, but anyone with respect for their budget or even for their backpack (sometimes the Sigma offerings are lighter & smaller) owes themselves the effort to compare when they go to buy a new lens.--David

I had a couple of 70-200 hsm lenses(the macro one and the previous version) which have rave reviews However flare was a real problem with both versions for me(I wonder if anyone had the same issue?)- so I had to let them go.However I still have 15-30(great results despite bad reviews)120-300, 15mm 2.8 those lense are well build and work as expected.

willi--Thanks for the heads up on the 70-200 flare you experienced. It's on my list to review when I get the time and I'll definitely look for that.--David

Hi David I will be interested in your findings! cheers,Will

I've owned and still do own many Sigma lenses, and as with Nikon some good some bad. The 120-300 f2.8 is one if the finest pieces of glass I've ever used.
the 24-70 f2.8 was the only option untill Nikon got off thier arse and made one which if far better than the very good Sigma.
The 10-20 is great, but replaced it with the 14-24 when I got a couple of D3's but the 10-20 is awesome.
I sold the 70-200 is was just a little unpredictable, but all in all I am happy with most HSM Sigma glass and if Nikon don't make what I need and Sigma do I will always buy.
Gav