I still find the copycat Las Vegas strip area of Macau disappointing and mostly weirdly empty/boring apart from the actual casino floors, which are segregated in a way they aren't in Vegas. The Portuguese villages on that side though, Taipa and Coloane, are still interesting (and Taipa has good restaurants/is walkable from the strip), and there are even beachside restaurants further afield that are nice, so overall it could be worth a day of time. The historic Macau peninsula old town is absolutely worth much of its own day as well. I usually go to Macau for about two nights.

You could stay the whole time in HK though and not really run out of things to do of course. For one trip splitting them of five nights you might want to consider one night in Macau, leaving your bags at the hotel early and after checkout for extra time on either side.