It's better to go early if you plan to have dinner during a weekend at "Heng Long Teochew Porridge". Otherwise once the crowd hits, the popular dishes go very quickly.
I find that the taste of the dishes has improved tremendously in comparison to the first few weeks of their opening. When I visited back then, the experience was a lot less satisfactory.
FYI - they also offer freshly-streamed fish for those who hanker after something cooked only upon order.

(Open daily from 10.30am to 4.30am).