Just back from a six flight, 15 day trip around SE Asia. Used the ANZ Black Lounge access twice.
SIN - small, basic facility. Free fish spa if you are interested. Basic food - help yourself fridge of softdrinks. Toilets are the public ones just outside. Best feature - great shower after a hot morning walking around town (and after coming in on a red eye). Lounge includes a paid spa, massage, etc area for various treatments.
DPS - upstairs in the new departure area - you can see it but it took a while to figure out how to get there - there is a temporary sign "JAS Premium Lounge" and you either use the small lift or the rather rickety temporary stairs. Lounge was almost deserted - as you would expect at 5.30am. Large space, nice fit out. Some lukewarm chicken sausages and potatoes. Some OK pastries, but I raided the fruit. Decent coffee machine. Help yourself fridge of softdrinks. Bathroom but I didn't see any showers.
In both cases it beats being outside in the general terminal area. I don't recall seeing alcohol being offered in either - not that I was looking for it. And I put amazing value in free wi-fi these days!!