Welcome to my nightmare
No effect on camera. Your write times for larger files will increase, though.

Air J
Your 80x card already exceeds the highest speed that the D70 can write files to the CF by more than double. The only advantage that a 200x card will give you is when you read the card from your computer which for most people is not that important. Stick with your current card.

keerok
Faster write times would be an advantage when doing continuous shooting and video. The faster write times will clear the camera's buffer faster to allow it to work at maximum fps.

OMG, I ♥ PONIES!!1
Rob Galbraith has a database for this stuff - here's the page for the D70s with various CF cards: As you can see, if you're using a decent card to begin with (and you are), buying an even faster card will only result in a tiny performance boost. That SanDisk Extreme IV card at the top of the chart is 266x. If you're shooting in RAW and take long sequences in continuous shooting mode, that tiny difference might matter... but not likely. The only real benefit is that you can transfer the contents of the card to your computer faster - provided you use a fast enough card reader. Please note that the D70s' top speed of 3 frames per second is determined by the camera itself. This has nothing to do with the memory card. A faster memory card only lets you sustain that shooting rate of 3 FPS a bit longer before the buffer memory clogs up. The D70s was obviously never intended as a sports camera, and the pedestrian FPS rate is evidence of this. The D70s also has mediocre high ISO performance by today's standards. This last 'shortcoming' can be mitigated to some extent by using fast glass. Basketball arenas tend to be poorly lit. If you're looking for a meaningful upgrade, consider body and lens options instead of the memory card. For the price of a faster memory card, you could also buy a 35mm f/1.8 or a 50mm f/1.8, or rent one or two superb lenses for the event. Or rent a camera and a lens. E.g. pop your CF card into a Nikon D700 (or even better, albeit pricier, a D3s) with a 24-70mm f/2.8, crank the ISO up to 6400 and shoot away.