Was in a meeting with a client on Friday showing a redesigned website that used Mega-dropdowns. Client said the site looked nice, but that he felt persistent left or right navigation was more useable than mega-dropdowns.
The marketing team at the client was pushing against persistent left or right nav because they said it made the site design feel dated. It does seem like it's fading ever since Jacob Neilsen published his article on the usability of megas.
I was asked my opinion and said it basically depends on what the user is trying to do. If they're navigating to a section and most likely looking for one thing among many options, then mega-dropdown should be fine. However, if the user is navigating to a section and has the need to browse across sub-categories in that section then some sort of persistent navigation makes sense.
Perhaps the best approach is not Either/Or but some sort of combination of the two schemes.
2 questions for the community:
1. What's your opinion of the usability of megas vs. old-school persistent left and right nav?
2. Have you seen any other forms of persistent nav schemes beyond the traditional left and right that work well?