The folks behind the maintenance of this library and their dedication to it really pay off. The wealth of comprehensive and up to date documented examples and It allows a singular developer to implement full-featured enterprise-worthy GIS solutions in a short amount of time that stand up to the product heavyweights in the GIS industry. Their ongoing integration with CesiumJS is also noteworthy, and though it takes some time to get immersed in the openlayers development process (the teams continual presence on stack overflow and github is appreciated), the truth is that the waters are shallow though they are wide. Leaflet has it's pros, but the lack of unity among the plugins is an issue for some applications, but Openlayers really does stand alone when it comes to delivering a fully-functional GIS solution application that gets out of your way when you need it to.