Ask HN: What is your support desk solution and why?

Right now, we have a team of 15 people with 2 on full-time support but we're growing and I want to make sure that our solution is good for now and as we grow. We use Zendesk but are considering other options very passively. Our main issues with Zendesk is that it is expensive, the data/analytics seem cluttered and convoluted, and the integrations (especially with Slack) seem to be lacking. I say "seem" because I don't feel like we know Zendesk very well, which could be one of the problems. What do you see are the negatives and positives of the solution you use?