The short answer
Pillow Talk is a warm nude-pink that reads as your own lips, slightly improved. Ruby Woo is a blue-red that announces itself from across a room and stays put through dinner. Nobody needs both, and the $34.66 between them is not buying a better lipstick.
Pick by what you want your mouth to do: disappear politely, or be the whole look.
Pillow Talk, $78.53
The warm nude-pink that reads as your-own-lips-but-better on a wide range of skin tones, which is why it sells the way it does. At $78 it's a lot for a nude, and it wants a smooth base to sit right.
The reason it sells is the shade rather than the formula. A nude that works across a wide range of skin tones is genuinely difficult to make, and this one does it, which is why it turns up in every makeup bag on the internet. Buyers rate it 4.3 / 5.
Its limit is texture on dry lips. A creamy nude sits in every crack it finds, so if your lips flake this needs a scrub and a balm first, and at $78.53 that preparation is not optional.
Ruby Woo, $43.87
Ruby Woo is the blue-red that has been in makeup bags for decades, and it holds through a meal without touching up. It is a proper drying matte, so put balm underneath if your lips flake.
It rates 4.1 / 5, the lowest of the makeup picks here, and the rating is honest rather than damning. A proper drying matte is uncomfortable by design: the pigment holds because the formula has nowhere near the slip of a cream. That is the trade for lasting through a meal without a napkin print.
The other thing to know is that blue-red is unforgiving of a wobbly line. It wants a steady hand or a liner, and it shows every bit of dry skin, so balm first and blot before you apply.
What the $34.66 buys
Not longevity: the cheaper one wears longer. Not comfort: the dearer one is more comfortable, but that is a finish choice rather than a quality gap. What $34.66 buys is a specific nude that is hard to match elsewhere, and a case that feels like something. Whether that is worth it depends on how often you wear nude lipstick, which for most people is far more often than they wear a blue-red.
If you own neither and want one, buy the one that suits the life you actually have. There is more on where makeup money does and does not change the result in makeup by budget.