They work well, but there is no reason to install one unless you need fix a broken choke. (it's cheaper than a cable most of the time) In my +25 years of playing with watercraft... I've only installed a primer on 2 of my own skis. Both were older, and it was not worth the effort to find a new cable. Currently, out of my 4 water toys... one has a primer.
Just my 2 cents