Right now I'm shooting with the A700 from Sony. Grew up on Minolta and then made the transition to Sony. I shoot all kinds of stuff - vacations, family, etc. But what pays the gadget bill is shooting for my website: www.powwows.com I shoot at Native American Pow Wows. Most of the ones I go to are inside arenas. I very rarely have good light. And with the Sony I'm challenged to keep the ISO under 800. Anything over that and the noise is very noticeable. So my first question is the ISO low noise as great as I hear on the D700, D300, and D3? I've seen some of Scott Kelby's photos that are at 4000 ISO and are incredible clear and noise free! Example: www.scottkelby.com/blog/2009/archives/7777 That's the main reason I'm considering the switch. But there are tons of little annoyances with the Sony system - non standard hot shoe for example! Next question, what's the differences between D300 and D700. They are about the same price. Are there major differences? I don't need video, just need stills. When I shoot these Pow Wows I'm also doing live video webcasts. So I have a solution for video already. What is DX and EX? How do the Sigmas lenses do on Nikon? When I switch my budget will dictate getting Sigmas to start. Then saving up for Nikon lenses. I shoot mostly with 3 lenses now - 70-200 f2.8, 24-70, and 11-17mm. Do the Sigmas work with both the D300 and D700? Thanks for your advice and suggestions!