I use DDG as my default, and I do like the bang syntax - in fact, it wouldn't be my default otherwise.

I find when searching for manuals on devices, for example, there are lots of garbage results or PDF spam sites that I would not recommend people click.

The other night I searched a question (I forget what) and the entire first page was Quora links to possibly the same question over and over, and not the question I asked.

tldr: I use !g, !i, and !usps a lot.