I like how easy it is to setup, configure & use! It's not as user friendly for newbies but has lots of features that can be used with little knowledge or training required. Calls are very clear even at high volumes (40+ people) without any compression/degradation in quality using Sipgate servers so far - haven't found another provider which works well yet. We've been able get away without expensive PBX systems by just having all our phones configured through clickit instead since we're small enough now where this isn't an issue anymore.