1) I'd just as soon go home - Does it mean I prefer to go home? or Something is just as fine as something esle (like #2)? 2) I'd just as soon go home as go to party. - Does it mean either thing is good?
When there's no context, it's hard to imagine the full meaning of a sentence.
I thought we were going to the movies not to that party at my ex-girlfriend's parents' house. I'd rather go home (do nothing) than go to the party (where I'll be very uncomfortable -negative).
I'm not as interested in the party as I am in the game we could play at home. I'd rather go home (and play the game - positive) than go to the party (also positive).