Advice on shoot with Sony HVR-Z7P - just purchased

Hi,

My video production company just purchased a HVR-Z7P which shoots HDV 1080i (a format I have shot in successfully before with a different camcorder). That will shoot in PAL 50 interlaced. This model also has a progressive 25P option. I am shooting an exercise video in a few days and I'm weighing up my options of the best way to shoot.When quickly experimenting 25p is jerky but perhaps this is because my shutter speed needs to be set to 25 instead of the 50 I use for interlaced?

I will be shooting in HDV and down-converting from the camera to Adobe Premiere Pro to edit in SD and release it exclusively as a DVD. No blu-ray is planned - its just good to shoot HDV for future proof I guess - and possibly the down-converted version is marginally better than shooting straight DVCAM (any one know?)

What I would like to know is what are the advantages of shooting 25p or should I just stick with 50i as this is not a artisitic film look that we are after? Would end result quality of the DVD be any different once its down-converted, converted to NTSC in DVfilm Atlantis and authored as an NTSC DVD for the international market? Yeah, all these formats make life so easy right!

Also anyone who knows this model of camera - can it shoot HDV to tape and SD to the CF card at the same time and visa versa? I know that's a lot of info I'm after but any advice would be greatly appreciated.
Cheers,
Ollie