Review this.

I'm not one to review things but I thought this would be a good time to start. We recently purchased a Sigma 70-200mm 2.8. I'm not going to go into super technical things here just to warn you.

The pros:

1 - Good build. You feel like your using a well made lens.
2 - Has a tripod mount on the lens which is helpful for tripod use.
3 - Quick, internal focusing and zooming. The lens stays the same length 100% of the time. The focus ring is on the end and is large making it easy to use. Manual focus with this lens is easier than most.
4 - Price. This lens is about 1k less than the Nikon/Canon equivalent.
5 - Sharp @ 2.8. This lens is much sharper than I thought it would be. Much better than my other two zooms, which was expected.
6 - Range. This lens has incredible range allowing you to get some great shots that otherwise wouldn't be possible.
7 - Because of the constant f2.8 and the range, this lens is an ideal lens for weddings and portraits.

The cons:

1 - I had to pay for it. Not that bad considering I saved so much over the alternative.
2 - Weight. You need to work out in order to use this lens. This lens is just over 3lbs. It feels like more being that its on the front of your camera. You need a big body to help compensate meaning a canon rebel(for example) would make it very difficult to use.
3 - Having just one. Melissa and I will surely be fighting over this thing, lol. Luckily we have a 85mm 1.8 which is a favorite of mine.
4 - Obviously this isn't the Nikon/Canon version. Those lenses will yield better results by comparison. Also, they offer image stabilization which is helpful with a long lens.
5 - While the focus is quick you will have trouble with subjects moving toward you. I'm referring to children with my experience. There tends to be some trouble with most lenses with this from my experience. It would be wise to us Continuous Focus function on your camera to combat this.

I also wanted to post a couple pictures for you to see. This are random shots taken at our home.