I have been on this hop-on hop-off evening cruise route for a few business occasions. It is by far one of the most well-received activities that you shall consider when in Hong Kong. While some would compare this experience with the normal Star Ferry/ other private yacht experience, I found this cruising experience is a perfect activity to consider for 1) hosting visiting guests from work to enjoy the spectacular harbour view over a few drinks 2) hosting friends who are in HK for the first time and love being in close distance with the harbour view.
Regardless, for this particular route please make sure to check in advance where you wish the hop-on and hop-off locations to be, also be on time and HAVE FUN!
The Aqua Luna cruise trip is almost fine to go on anytime throughout the year, would suggest avoiding the typhoon season though in case it pours heavily when you're on the cruise (which can kill the mood).