Panasonic's manual, unfortunately, isn't too specific about the widescreen capabilities of the GS400....

Here's the way I read it:

Cinema function records a letterboxed 4:3, 60i image

Wide function records 16:9, 60i image (is this a true 16:9 or some other strange feature? Is it anamorphic?)

Pro-Cinema function records 16:9, 30p image (is this a true progressive shooting feature, or is it another weird thing they have done that isn't true progressive filming?)

If the image is progressive, what will I have to do, if anything, to make sure resulting dvd is compatible with players?

Try this: http://panasonic.jp/dvc/gs400k/colorful.html

Jeremy, the GS400 has a very high quality widescreen mode with little to no degradation of image quality. The widescreen function (not cinema mode) is anamorphic so that the 853x480 widescreen image will fit into NTSC's 720x480 4:3 standard.

The GS400 uses frame mode instead of true progressive scan. You can do a search in this forum and find a wealth of information on the differences. Also frame mode and progressive scan is simply a way of capturing and will not effect your DVD.

I really like GS400 16:9 mode.