What HDMI 1.4 overcomes is the reliance of an alternating frame system to deliver 1080p 3-D by offering simultaneous 1080p streams. *This* is what HDMI 1.3 can't do. How this affects the end user depends on their 3-D display. It hasn't really been discussed in this thread yet, but all alternating frame 3-D systems will have (to varying degrees) "phasing" issues. Notably with motion at a sympathetic rate of the alternating cycle which is used. This can be seen with certain pans or motion in theatrical polarized Real-D, as well as the Dolby / Infitec system, which both uses alternating frames @ 144hz in order to be able to use one projector. Only IMAX uses twin projectors, and therefore avoids these potential phasing issues. The faster the alternating frames, the less obtrusive this type of artifact becomes. However- With a 3-D display device (be it a 4K display device that can offer L/R stereo content at 2K via polarization, or dual projectors) that doesn't need alternating frames, these issues can then be easily bypassed with 1.4, as it has the bandwidth to offer both streams in a better form.