I own three shades, Crush, Honey and Darling, and I think they're all fantastic. They are the only lip product labelled as 'moisturising' that I have tried that I would consider to be actually moisturising and not just a tagline to entice buyers. The pigmentation is predictably inconsistent throughout the range as the darker shades are a lot stronger than the lighter shades, which apply quite sheer. Another thing about the balm stains (that I have heard many people complain about) is that they have a lovely minty smell, which I think is lovely. They leave a shiny, but not glossy sheen to the lips. The stains are light, not sticky and they complement rather than cover your lips natural colour, and so I feel they're really quite versatile! They also come in a range of 7 colours (I think there are a few more in the US though), from dark red to bright pink to light lilac so there's definitely a shade to suit everyone.
Crush is a dark red stain with a slight hint of brown. It has a tendency to apply relatively sheer, but can easily be built up to a strong base. Due to its colour, it stains very easily, and thus can last a good 4-5 hours.
Honey is a muted rose pink, which I think is a perfect everyday colour. It requires a few layers to get a good coverage, and it doesn't seem to last as long or stain as much as Crush (maybe 3-4 hours without eating)
Finally, my favourite (just because it's purple :3) is Darling. Darling is a blue based lilac-pink, which reminds me of Barry M's Palest Lavender and (from swatches alone) MACs Lavender Whip. Being the lightest of the three shades I own, it is predictably the least pigmented, leaves only the slightest stain, but still has a good life span of maybe 3-4 hours.
Darling, Honey and Crush
Revlon Balm Stains retail in Boots and Superdrug for £7.99
Have you tried the balm stains? What did you think of them?