I can't say I've tried LA Splash (although they're on my to-buy list) but I have Sleek's Matte Me in Birthday Suit and Petal.
Petal is a much brighter pink in person than it looks on the tube, and Birthday is a good nude (I think it's like Ghoulish or LC's Cashmere but I havent looked into it that much).
I'd say the formula is pretty drying, and lips need much more moisturising than other liquids I've tried. It's very easy to use too much products, so you need to continually wipe product off the applicator, and it's staying power is pretty meh - possibly up to 4 hours until it starts to flake without eating/drinking?
For £5 it's a good buy though, it helps if you line your lips completely and i've often taken to using them on top of other lipsticks