The Atomos Shogun 4K HDMI Recorder is continuously becoming more and more popular with more cameras supporting clean HDMI signals. Instead of your camera recording to a compressed file to an SD or Compact Flash card, the feed is recorded in the Shogun to a variety of high quality formats. Aside from just being a recorder, the Atomos Shogun is an amazing full featured high resolution monitor with waveforms, peaking, zebras, and more. The fact that it can see a 4K signal also makes this ideal to monitor from such cameras that only output 4K where other monitors won't work.
HDMI itself though can be problematic as there is no locking mechanism to keep the connection solid, and as the cable protrudes, there is the possibility of damaging the HDMI port. If you're working with the Atomos Shogun, and want to instill a higher level of confidence, check out the PVGear KavalCage with HDMI Locks designed for the Atomos Shogun.
At almost $2,000 dollars, I think the Shogun's ability as a 4K Recorder, Monitor, and Audio Preamp makes it worth every penny, but it might be worth spending a few bucks more for the PVGear KavalCage system to protect the Shogun during use.