You can talk numbers until you are blue in the face, but it’s really down to how the pictures look on the monitor and what sort of work you want to do with it. If you want to key, then HDV is functional, but no better than DV as Graeme says (he’s also right about HDCam – I was so surprised when I tried to pull my first HDCam key – it was as tricky as DV!)
However the image quality from HDV is very impressive, we have replaced our PD170’s with Z1’s and have had no real problems. Sure the HVX will certainly be better quality, but it’s not out yet and you have to be able to fit in with the P2 workflow.
The simple answer is try it yourself and see what you think!