Sanding drywall after primer

I hear some people suggest lightly sanding the primed drywall to knock down any debris and remove raised grains, etc. for a smoother final finish. Some suggest doing it between the two top coats as well...
It sounds like a good idea to me, but I'd like to hear people's opinion here on whether that's worth while.
And if yes, what grit of sand paper would you use? (I'd be using a pole sander).

 

I usually sand lightly between coats and normally use 120 grit on my sanding pole.

 

I second what Marksr suggested and would add that after sanding I vacuum and wipe down with a damp cloth or big sponge before applying next coat of paint.

 

Lightly sanding between coats is SOP (standard operating procedure) for a quality professional paint job. Nothing wrong with omitting it if you shine a light on the wall and it's perfect, but painting right over the top of imperfections is not the best method. Some people would never notice the difference either way, but a painter that is meticulous would.

 

New drywall tends to fuzz up when primed so it benefits from sanding. If working conditions aren't clean enough or windows/doors are open crap can blow onto the wet primer/paint. Basically all you are doing is dragging the sandpaper across the wall - hardly takes any extra time. While it's always best to use quality coatings, they aren't a free pass for not doing the prep.

With new drywall or repairs there is often sanding dust that needs to be removed. Some do like Paul and wipe/vacuum it all off. I just brush it all down with my push broom [minus handle] to remove 90% of the dust. What's left has never posed a problem.

 

Thanks everyone! I don't think it would take that much time and I've been spending a lot of time already learning how to do each step right to get good results... no point in skipping a step now!
I'll give everything a light sand with 120 grit between coats!