My family used to love Rong Guang when it was at Alexandra village- since it moved, we've tried it twice at gluttons by the bay.. Unfortunately, it seems that the standard has dropped significantly. In our latest trip, we ordered a large sambal stingray, Ngoh hiang (deep fried prawn rolls) and a fried Kai lan. The nicest dish of the night was the vegetables and this speaks volumes. Stingray seemed to have shrunk and only the surface sambal was hot, the insides were cold - one wonders if they'd even bothered to heat up the hot plate. Certainly didn't sizzle like it did before in Alexandra village. Prawn rolls were edible but over fried. 
Look around the tables at gluttons by the bay and you'll realise that a lot of tourists are having this stalls Chilli crab instead. Not sure if the stall promotes it instead but we really miss the good ol' yummy stingray of before.