Movie Making Manual/HDV
HDV vs DVCproHDEdit
DVCproHD will probably produce better results than HDV. DVCproHD uses a chroma subsampling of 4:2:2 (i.e. it records a full-resolution lumanance image and a half-resolution colour image) whilst HDV uses 4:2:0.
DVCproHD also uses a much higher bitrate (100Mbps) than HDV (25Mbps). But that doesn't mean that DVCproHD will be 4 times "better" than HDV. HDV is a more efficient codec than DVCproHD. And, if you're shooting at 24fps then you actually throw away a lot of DVCproHD's data.
There's an intersting discussion of HDV in comparison to other HD formats on episode 2 of the recent Creative Cow podcasts: