Do the Compact poles save any space in,...
Do the Compact poles save any space in, or on, your pack, when they are retracted and stored, over the standard poles?
Misused commas aside, yes. They collapse to a shorter length.
A collapsed pole (27") is about the length of an overnighter/weekend backpack, where as your extended non-collapsible pole is going stick out the top of your pack by 15" or more. The collapsible polls are the way to go.