This is one of those questions that if you ask 10 people, you'll likely get 12 different responses. So much depends on your hair properties (texture, porosity) and the ingredients in the gels and mousses. Personal preference also plays a huge role. For the most part, I like a strong gel in the humidity of summer but a lighter mousse during the cold, dry winter days. I find most gels too drying in the winter. I resolve the issue by making my own FSG. The ingredients are cheap and easy to find. It takes 15 minutes from start to clean-up. I can add anything my hair needs at the time. My favorite additives are honey, glycerin, epsom salt, protein, essential oils. Not necessarily all at once and in differing quantities depending on the weather.

If the mousse works for you - keep using it. The product junkie in me would want to test out the gel just for comparison.
3B, fine, normal to low porosity
Modified CG since June 2010
HGs: FSG, anything with glycerin, Tresemme Naturals conditioner, Curls Like Us cloths, satin pillowcases.