I find they offer really opaque coverage with thicker consistencies that do well for smoothing out the area, but they sometimes seem to crease more readily on me and take some practice (and the right applicator/product) to set as they are already thick.
From my experience, they can be less pigmented if they’re thinner (but easier to spread, though they can be streaky if you’re not careful), whereas they can be really pigmented but harder to spread if they’re thicker.
When they’re done right, they can give the skin a great, natural finish that doesn’t look powdery, flat, or heavy, but sometimes they can look oily, slide off the skin easily, or have more visible shimmer particles!
They’re almost always a product that performs well for one but not both, so I’d rather buy a unitasker in this instance. It’s hard to get something that’s hydrating/emollient for lips that doesn’t then slide off on cheeks!