To click, or to hover

The sub sections of a main menu should only appear on click...discuss.

Lately I've been experimenting build methods for a monster navigation menu (we're talking 5 levels deep, content heavy).

Obviously with mobile being such a heavy focus for this particular client, I've been experimenting with a click event on the main nav item over a hover event.

There are drawbacks to either approach. A 'on hover' event won't show on mobile (but then perhaps a mega menu isn't the best solution) and an 'on click' event won't allow an href on the master menu page.

Here's an example of the 'on click' that I like and I think works very well on mobile too http://newwordalive.org/ and of course here's a hover example I built - granted it's not responsive - http://www.underarmour.com/.

I remember sometime ago some ExpressionEngine devs were complaining about the necessity to click a menu item in the control panel for the sub items to appear and that it seemed to be an accessibility decision.

What's your opinion?