Dalite Silver Pacer vs White Matte screens?

I have a 40" x 40' silver pacer screen that I bought new in the 80s. How does it compare to a matte white screen (recommended by Leitz), of the same vintage, for slide projection, please?

Without specific data available for your screen anymore, in general silver screens give a much more specular reflection.
That means higher reflection, but over much more narrow angle.
Which means spectators must sit nearer to the optical axis.

The info I have says that matte white screens have a narrower angle of view.

All matte white screens have the largest angle of reflection (spreading of an incoming, perpendicular ray) amongst all classic screens.

You easily canb check this if yout have a matte white wall in house, or large sheet of white paper/cardboard.

White matte screens:
Images are sharper, and can be seen from almost any angle.
Image not quite as bright as a silver screen.
Not compatible with polarized stereo projection (double image results as polarization is scattered).
Silver lenticular screens:
Brighter image.
Compatible with stereo projection.
Image becomes dimmer as spectator leaves axis.
Lenticular screen pattern can form moiré patterns if things in the image (e.g. picket fences, automobile grilles, international style building exteriors) that have patterns of their own are in the image.
Silver matte screens:
Brightest of all, no moiré patterns.
Image bright only in the direct line between the projector and the screen.
Image as a silver reflection may look "false" to some viewers.