Sigma 300mm f/2.8?

Looking to upgrade from my Nikon 70-300mm VR... I've pushed beyond this lens' capbilities. Heard good reviews about the Sigma for what it is priced. I really don't want to spend $10Gs on Nikons new 300. Suggestions... Advice.... Thanks!

Some good reviews worthy of consideration here in our Reviews section. http://www.photographyreview.com/cat...1_3111crx.aspx
Definitely worth considering as an alternative to the super high prices of the Canon and Nikons as you stated. Build quality probably won't be as good but if your not a working pro that will be banging it around all the time it should not be a problem.
I'm considering the Sigma 50mm1.4 myself as an alternative to the Canons 1.2 and 1500.00 price tag. the reviews for that Sigma lens are outstanding, and so I will most likely go for it.
I would say go for it if money is an issue. . .

Is 300mm really your main purpose with your zoom len? I'd say a 70-200 f/2.8 is a lot more useful than a fixed 300, a fixed 300 is very much a specialty lens. Are you specifically wanting something that super telephoto?

I'll use this lens mostly for "birding" and distant wildlife shots...

Well, 200 is a bit short for birding, and even short for some wildlife, and as you emphasize 'distant' wildlife, the 300 might be ideal. In fact, the 300 might even be a bit wide, but those 300's are so sharp you usually have huge crop leverage anyway.

I'd at least look at some of the super telephoto zooms as well, you wont find anything at f/2.8 fast. Sigma also has a 100-300 f/4 that people give great feedback on. Its damn fast for a telephoto zoom, and you'll have the zoom range as well. Yeah that and the fact that its also 1/3rd the price of their 300 f/2.8.

Not familiar enough with Nikon's super telephoto zoom range, but I'm sure they'd also have something similar.