Liquid Silk is a hybrid, and hybrids just don't mesh with me. It's supposed to be the best of both worlds but it ends up being the worst. It can't be used with silicone toys, and when I'm not using a silicone toy, a pure silicone lube is miles ahead of Liquid Silk in every department.
If I had to choose, I'd go with Maximus, but both Maximus and Liquid Silk are rife with parabens and have way too many ingredients in my opinion.
Sliquid all the way!