We used it locally at megacorp in place of the standard JIRA instance. As an end user I disliked it because it was painfully slow and the interface was awful. It broke browser navigation, if there were permalinks they were nearly impossible to find so most things couldn't easily be bookmarked, filtering was tedious and unintuitive. Some coworkers tried to write CLI tools and the API turned out to be as awkward as the web UI.

Ideally we would've just thrown more money at CloudBees, but there was no political will to fight for another paid JIRA instance. I'm sure there are worse tools than snow but I'd just as soon never use it again.