Luxrender is a well-known renderer and some commercial render farms officially support it, so you can submit jobs and have Luxrender work for you in the “cloud”.

Luxrender takes full advantage of OpenCL and CUDA toolkits, so it can use every last available resource to get your renders out as quickly as possible.

Luxrender features professional-grade features, including lighting groups, volumetrics, instancing, motion blur, depth of field, tone mapping, de-noising, and much more. This is a serious renderer.

Luxrender is a serious, professional renderer. If you're just learning how to model or light, it might be overkill as an initial rendering setup.

Many of Luxrender's most advanced features expect you to have a powerful computer with a powerful GPU.