I can't speak for the Photoshop -> Photo transition since that's never really been my thing, but if you've been using CS professionally for any length of time t

I can't speak for the Photoshop -> Photo transition since that's never really been my thing, but if you've been using CS professionally for any length of time then going from Illustrator + InDesign to Designer + Publisher take some significant muscle memory retraining. I've been gradually switching over for the last ~6 months but I still have to reach for Ai or Id if there's a really time-sensitive task. The amount of subconscious automation that goes into making you really proficient at using some tool becomes very obvious when you try to use a different one.