You really don't need cineform. I've been editing hdv A LOT natively in pro 2 and it works pretty well. When I export to AE I have to export in uncompressed 4:2:2 as AE doesn't really do native hdv. There are no quality issues whatsoever compared to non-native editing. It will look actually better as there are no compressions to another format.
I've been doing color corrections, slow motions, special effects and everything works well. Here's a clip to a small test action scene we shot.
http://hmcindie.pp.fi/suomenlinna/En...%20quality.wmv