Hi.
I purchased the HTC Vive and I'm very pleased with its room-scale capability, as well as with the lighthouse technology. The two lighthouses:
* do not need to connect to the PC, just power.
* they are located at the corners of the room, to provide full room coverage, which I doubt is technically feasible with two USB cameras.
* they can be used by ANY number of Headsets or Controllers. They only emit lasers and IR light. It is the controller, which detects and transmits its location to the PC.
Also, I'm pleased with the length of the cable.
However:
* I am unhappy with lenses of the VIVE, because they blur up to 20% of the image on each side (left-right) - this is not an issue on the upper and lower edges of the lenses, significantly reducing the useful & effective field of view, and they suffer from visible colour aberration. They are made of plastic, they are cheap.
* as you said, the VIVE headset and its longer cable are significantly heavier.
* the controllers are also significantly heavier and you do feel it after a while.
* to take full advantage of the lighthouses, you need to install them permanent on your walls and the power cords are ugly. In the longer term, redecoration of the walls is unavoidable...
Does the camera on the VIVE make a difference? I don't think so. It caused issues with my headset's tracking and HTC's advice is to deactivate it, hence, the camera is currently adding to the cost of the headset without real value. EDIT: There's a configuration option to decrease the frame rate of the camera from 60fps to 30fps, to reduce the workload on the USB connection.
I wish OculusVR had been clearer about the cost of the upcoming controllers and secondary camera, as well as about room-scale VR. My concern is that the Oculus solution may eventually cost as much if not more than the VIVE.
I hope this helps.