The ability to grab items and move them where I need them is one of the best features. I work partially in VR development, and being able to test how coded physics and object interactions actually respond live from the computer we code from before compiling a build saves so much time.

Their technology and the way I can feel virtual things in real life.

Wide range of plugins, many examples to start with, excellent documentation, support of multiple languages and SDK with great ease of use. Been using it since its Beta release. It has improved a lot since then.