Installed after seeing a friend's positive experiences with it, and did a little testing to see what it could save. As far as saving money goes, it works quite well for several popular sites.

Immediately after installing, however, the performance of the browser slowed to a crawl. Changing tabs took forever, loading tabs took twice as long, and anything relying on a plugin (Flash, Java, other) would hang the browser and the entire computer for as long as 5 minutes. I tried closing tabs (I usually run with two windows and 120+ tabs open), but this had no effect. I'm running Mac OS, so I pulled open a terminal and ran top, sorted for CPU and RAM, and found nothing increased from prior to the install. I then cleared all temp files, disabled all plugins (Honey, Noscript, Self Destructing Cookes, uBlock Origin, and Tab Counter), and then enabled them all one at a time, leaving Honey for last.

Enabling Honey reduced the performance of the browser immediately to a crawl, and disabling it immediately restored the performance.

Between the privacy implications of the plugin (http://www.novatexsolutions.com/blog/v/honey-is-watching-you/) and the performance issues, I will be at least leaving the plugin disabled except while checking out. If I continue to have performance issues, I'll just uninstall it entirely.