Since this feature
requires rotating and zooming the chart data to match the radar
display, vector charts are clearly the right choice.

Hmmm, no it doesn't. At least not on a Raymarine E-80. I can overlay radar
on top of charts in any orientation. I tend to prefer North up orientation,
but the admiral likes it to rotate with the heading. It's a snap to change
between them.

When dealing with charts at the helm I find vector more useful. When
plotting courses on a laptop, however, raster seems better. For me the
difference is what I need to know RIGHT NOW versus planning what I where I
feel like going at some later time. The vector charts with the ability to
zoom in/out quickly and without losing detail (getting grainy like raster)
are of tremendous help when actually moving. Granted, I'm usually at 30kts
in a powerboat; those in sailboats might have a different sense of urgency.
But when I'm planning trips ahead of time I find the extra detail they've
got on raster charts to be rather handy. I generally use Coastal Explorer
(aka Maptech Chart Navigator Pro) with Maptech digital charts. On the
chartplotter I use a Navionics platinum chip.

If faced with having to choose one over the other I'd probably go with
vector because of it's benefits (for me anyway) while underway and just use
other sources for trip planning extras.