Past the learning curve, a great product

Manage sales funnel, our customers, and marketing efforts. Hubspot allows us to accurately track opportunities, customers, and a variety of sales/marketing KPIs. The Pro level is fairly customizable, the Enterprise even more so. The level of customization makes for a steep learning curve in terms of implementation, but gives you a lot of control. It can be difficult to figure out what you want/how to build something, but their level of support is top-notch. You generally have a dedicated CSM you can book time with for learning sessions, but their chat and email options are really great for quick questions or if you're stuck on best practices for something.