Well, I haven't spent nearly as much time with Publisher as InDesign, but I'm getting there. I do realize there are functions in ID that aren't in Publisher.
One thing I find problematic is that you can't view a single page if you're working on something with spreads. I do a lot of book correcting, so I need to see each page as large as possible. In ID I use Cmd-0 to Fit Page in Window. In Publisher it seems that if the job is using spreads each spread is shown as a "page" so even if I use Zoom to Fit I have to switch to the hand tool and manually center and enlarge each page so I can do the corrections accurately. It's not a deal-breaker, but it's clumsy.