I preach 7 to 9 links is the best-case requirement on a home page. So I choke on “link clutter”. That is frequently beyond a designers control since it’s probably edict from a committee.
I have low-expectations of dropdown and flyout navigation. I am prejudiced about dropdowns for various reasons. It is mostly a matter of preference and lack of tolerance on my part. Consider it a www personality disorder of hypersensitivity.
The responsivity of a CSS3 dropdown menu is “snappy”. This has pros and cons. Flashiness is one con. It can be somewhat distracting or surprising –like a winged bug jumping in your face. But I’d rather have a snappy responsive navigation than one that’s a slug.
A complaint with all dropdowns is what happens during accidental rollover like when accessing the browser back button. This is inherent in all dropdowns not just this one. So it’s irresolvably disturbing. I find it annoying on all sites. I am not a qualified person to judge the usability appropriateness. That is an endless debate on the web. I can say, “CSS3 cooks and looks good.” When there are too many links, dropdowns are the best game in town to compromise. Being weightless is the biggest coolness factor for me.