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Summary - 1.4 or 1.8 glass - D700 or D7000 if you have a lot of DX glass.

Anything is a massive step from the D70.

What's your budget? Any preference to DX or FX? D3S is definitely the best for low light, but I'm assuming that's out of budget and too big. A D700 is great, but will probably get updated next year and is still pretty expensive. I think a D7000 would be great for you since it's not much bigger than a d70, and will probably have a long life like the D90. It has a newer focusing system that should work great in low light. You should also consider getting the Nikkor 35mm f1.8 AF-S since it's so cheap.

I take a lot of dance event photography (very low light, flash not permitted) and I've been using a D70 and although I can get some good photos, I have felt very limited by it in terms of ISO and noise and speed, and especially the teeny weeny viewfinder. Currently I only have one lens, a prime 24mm f2.8, and been lent a kit lens which isn't good for low light. The autofocus is rubbish in low light, so have been focusing manually, which with the viewfinder so small means I can't tell quickly if what I want is in focus.

Would like to upgrade, but just can't decide if to get the D700, D300s/D300, D7000 or switch to the Canon EOS 7D. I love the feel of the 300s, but have heard it's not as good as the D7000. Never managed to get my hands on the D700, but worry it will be too heavy. Any advice? Amazing and colour and fast focussing is the priority... Also do portrait, and aiming to go semi-pro.

Eventually would like to get the 50mm f1.4, 85mm f1.8, 24-70mm f2.8 or the 17-55mm f2.8 and also the 70-200mm f2.8 - which do you think I'd get the most out of getting first? Assuming I normally get reasonably close to the dancers/stage?

Please let me know what you think...

Many thanks,

Heather