Hello @cforge,
Thanks for updating the thread. 
Going by the general practice most of the time we see Navigation Dropdown kind of effect on mobile devices. However, as the web is evolving there is a need to come up with new interfaces that can comprehend changing landscape of the websites.
There is no denying that we are putting up website to reach our target customer base. Here is something I can suggest you. Let’s design two headers. On one header let’s have Navigation Collapsed element and on other header we can have Navigation Dropdown. Once you are done with this, assign respective header to couple of pages. After doing that, you can share the URL’s with your friends and family and request them to test it out and see which one they like to navigate. Doing so will give you a rough idea about there behaviour and which one they are liking. It’s just a personal input from my end, hope you don’t mind.
Thanks.