The pro workflow would answers to type of export at first :
- export sequence (with optimal render )
- export on tape.
After, once you have the best digital master you can (1920x1080 10bits render) you will encode it to whatever you need...
I recommand turbo.264HD (I love things goes fast when encoding
But if you want to transform you 40' in a hd like on 2 Go an MPEG2 at low rates would be fine or 640x360 H264
Like DH said : it depends... And it depends also of the subject if it just a guy speaking or an army of ants invading a football match of hedgehogs...