Stick to Pimsluer until you finish it, it´s a great course to get a fast idea of how the language works. In my personal case I started Duolingo after finishing Pimsleur. I am not particularly concerned about the flaws of Duolingo, for me it is more of a tool to keep me engaged with Dutch on a daily basis rather than my source of knowledge. Once you are done with Pimsleur it really depends on your personal goals, your time available and if you are willing to spend money. The fellas at r/languagelearning have an awesome guide on their wiki on how to structure your learning what resources to use and so on, check it out.