My favourite Wooga variant of jjajangmyeon turned out to be their humbler yooni jjajangmyeon.
Instead of bulgogi or pork belly, this came topped with minced meat. I preferred this variant because the minced meat retained its juices and made the black bean sauce more savoury and flavourful.
At this price point, I think Wooga presents a really good bowl of jjajangmyeon. In terms of 1the proteins, I certainly prefer the Jeong Jjajang which comes with seafood. As for the sauces, it boils down to a matter of personal preference - do you prefer a sweeter and glossier sauce (ie Wooga) or a more savoury version (Jeong). Both are great but I personally prefer the later.
P.s. Jeong has since shifted a shop space and naturally increased its prices. Other than Wooga, I can't think of any other hawker stalls which serve a bowl of JJM at these prices!