I'll second wood filler.

Glazing compound is oily which will cause paint adhesion problems, flash & bleed thru the paint.

I like Dap's Drydex spackle. Goes on pink, dries to white. Minimal shrinkage; sands easily.

For painted surfaces spackling over wood filler for sure.

For nail holes my professional painters always use Onetime lightweight spackling made by Red Devil. They say it doesn’t shrink as it dries like wood filler. It’s very easy to sand smooth.

Glazing compound does not sand well, and it takes a very long time to set up too. I did a window this spring, and had to wait until this fall before it was set up enough to paint that area. Certainly not used to fill nail holes. I like red devil spackling too. Works great.

I agree that spackling is easier than wood filler, but wood filler is more durable, and I find that spackling can dish out more easily when sanding to get everything flush.

Very true about the over sanding. My painter uses a small block of wood with a piece of sandpaper glued to it. Sanding the spackle gently with the block of wood keeps it from cupping. After that just a gentle swipe with a sanding sponge to form it exactly to the curve of the trim.

Glazing compound has a looooong cure time. Wood filler for wood, spackle for sheet rock and plaster. Use similar materials for the best results.