OK – this is a much debated topic over at the HDV forum and there is a running thread over there at the moment if you want to take a look including some insight from Graeme Nattress.
If your rushes are all in HDV then it makes most sense to capture them native via firewire.
Do your edit in native HDV, despite all the hype editing in HDV on a reasonably fast Mac has no problems at all, you get lots of real time including scaling and colour correction and the long GOP structure doesn’t affect the edit process.
When you are finished, simply drop your finished timeline into a new ProRes one and render it out. This means all you CC and FX will be rendered out in high quality. At this point if you have a Kona or a BMD card then you can master to any HD SDI deck.
We don’t bother doing the conversion on ingest as the HDV codec is actually very space efficient and easy to edit with.