I also use Superdeck and like it. Its not a film forming coating, so its easier when it comes time to strip and re-do. You could go with a film forming coating and get a longer lasting job, but the downside is that its more work to strip when you have to re-do.
I've never used Sikens, but have heard really good things about it. If its avaliable in your area, I'd look into it.
Nice looking patio by the way.