I too was reluctant of using many of the new ES6 features, but as I've begun to adapt them I've come to appreciate them a lot! In fact, when using Babel to compile ES2015/2016 you can in many cases rid yourself of things like Underscore/lodash[1], Promise libraries, etc.
I've recently started a new project in React/Flux, and I've cut away 3 or 4 dependencies compared to previous projects by fully embracing ES2015/2016, as Babel automatically provides the necessary polyfills and compilation.
As for template strings, I think they make sense. Most programming languages have them in someway or another, like Ruby "hello #{world}" or Python 'Hello {world}'.format(world='World').
lodash has ~200 modular methods. That means it covers much more ground than the handful of ES5/6 built-ins provided and because it's modular you can use what you need without the stuff you don't.
I've recently started a new project in React/Flux, and I've cut away 3 or 4 dependencies compared to previous projects by fully embracing ES2015/2016, as Babel automatically provides the necessary polyfills and compilation.
As for template strings, I think they make sense. Most programming languages have them in someway or another, like Ruby "hello #{world}" or Python 'Hello {world}'.format(world='World').
[1] https://www.reindex.io/blog/you-might-not-need-underscore/