CSS: Are view height (vh) and view width (vw) units widely supported?

use both CSS vh and jQuery, it's safer.
jQuery example:

var clientHeight = $( window ).height();
  $('.element').css('height', clientHeight);

and CSS:

.element {height: 100vh;}

The statistic is clearly and it is a fair assessment, in my point of view.

I think the decision has to be made by you. If you want to future-proof your website using the latest greatest technology, but are aware that there are currently some downfalls, then great, go for it.

If you are not prepared to invest a little more into your online presence, then stick to the old way, which is in no means wrong.

EDIT: When I want to create a responsive design I start developing for Mobile Devices first and then create the Desktop Version, to ensure that my viewports all work correctly, since the Mobile support is lacking at some points(especially vmax). BUT about this you could ask 50 guys and the chances that they all will say something else are pretty good.