I'm just finishing my first project with the JVC GY HMQ10 for video and a d800 for raw time lapse and I have to say the results are astonishing. I'm not sure what it is about this camera that's causing people not to use it but honestly this is the best looking footage I've ever shot. I'll post samples when finished.

4 x SD cards probably.

4 x SD cards probably.

This. It's not a big deal, but it is an unusual way of recording 4K.
I really like the concept, however, and applaud JVC for offering the lowest priced 4K camera, by far.
But I simply have no use for 4K right now. If I bought this camera, I'd end up using it as an HD camera, and for that, it becomes an overpriced, 1/2.3" single CMOS AVCHD cam. I could get a much cheaper NX70 and get close to the same results (I think).
But yeah, I am intrigued, but haven't decided to swap my FS100 for one just yet.

Duane, did you shoot in 4K and downgrade to HD for the finished project? Perhaps that would give a really nice image, better than other one-chip cameras. I don't know enough about this camera to know its workflow, or how much 4K video will tax an NLE. Please tell us more about your experiences with the HMQ10.
I look forward to your video. The stuff I've seen on YouTube and Vimeo looks very impressive.

1. 4 x SD cards.......not so bad
2. Live output via 4 x HDMI cables which need to be plugged into 4 x HDMI ports on a 4K HDTV.......very expensive or hard to find or both
3. A system to edit the 4 quadrants of the highly compressed Quad HD stream with acceptable performance......Umm

There is not any doubt the 4K image even from this low cost JVC camera looks superior to most 1080p images based on what I and virtually everyone who saw the live video/ exported compressed 144 Mbps clips shown on a 4K HDTV here recently. When it came to the required infrastructure needed to create content for it in the next 1-2 years, everyone had serious doubt.

Maybe with the 4K sets' prices coming down, more higher end cameras like the Sony F5/55, Canon C500, EOS1-DC etc coming to market and more people experiencing 4K content, there could be some viable market for it. As for casual shooting and viewing, the cost of the GY-HMQ10 itself is not a barrier but the costs of the rest before the video gets shown on the screen are.

I've found there to be only two annoyances with the camera. The first is the use of 4 cards as mentioned. This adds all of 60 seconds to the work flow when transferring files though so it's a small price to pay in my experience.

The second is the lack of ND filters which are a must. But, it takes about 5 seconds to attach a filter so this hasn't been an issue when shooting.

My workflow at this early stage has been to use a 3840 x 2160 project in P.P CS6. That way I can drop the original files into the timeline and edit without having to render to a master file. P.P. actually plays these 4k files without stuttering.

I've been rendering to 1080p as I don't yet have a 4k monitor but the difference between the 1080 clips and 4k is like night and day, even when viewed in standard HD.

Another issue is the optical quality. The lens has not enough resolving power to do 4K justice. I had the camera for a week for review and was sort of puzzled by the look of the video.

A Canon EOS C500 delivers 4K in a startling quality, but the GY-HMQ10 delivers something that looks like glorious 1080HD. If you start pixel-peeping, you will find that 4K video it delivers lacks detail.

One of the big advantages in using 4K is in my opinion the 3D pop that the added micro-contrast gives. And GY-HMq10 simply does not have this. Since the sensor is only 22,05 square mm, and a C500 sensor is 2370 square mm the optical quality has to be optimized for the smaller sensor in the JVC camera. To my eyes it look like a HD optic on the JVC.

I am definitely not saying that that the GY-HMQ10 is delivering bad quality. I am only saying that the 3D "pop" is missing from its 4K footage. And that "pop" is what drives 4K as differentiator IMHO

Completely agree that the JVC is not a C500. But don't agree about the lack of 3d effect with proper settings and filters. Comparing the footage directly to the time laps raw footage from my d800 (which are actually 7.5k raw files), the JVC holds its own in terms of perceived resolution, at least on a 1080 screen. If any of the settings are set to auto it compromise the quality as the camera will control brightness by increasing shutter speed. It's possible to drive the camera into a very soft look in auto mode but when using filters that doesn't happen. I've also noticed the 3d effect is easier to obtain when shooting 60p rather than 24p, and with a shutter speed between 60 and 120.

I sit corrected ... to a degree.The camera does have some 4K pop, but you have to hit the sweet spot, meaning optimal lightning conditions. As soon as gain creeps op over 6 dB, you get a smearing from the noise reduction circuts. It is sort of an anti "4K pop" filter.

I have been shooting indoors a lot with the camera, and was not impressed. How ever the one and only day with some bright sun in the period I had the camera did give some shots with pop. But since I did not have any 4K monitoring in location it was quite difficult to judge the "pop"-iness of the takes.

If I was living in say California, I would probably love the camera.

Yes it's not a great indoor camera as it needs quite a bit of light. I'm using it for exterior scenery, views etc which require as much detail as possible. In that capacity it's amazing considering the price. I would prefer a c500 much like I would rather have a Ferrari than the car I'm driving but then there's reality.