In general, I'd agree that the D750 is currently the most refined 1080p hybrid DSLR Nikon offers. Like all Nikons, however, the D750 has a few crucial limitations that impair its usability as a video camera:

• 4GB maximum file length limits each video to less than 30 minutes.
• Lack of focus peaking makes it essential to use an external monitor.
• Primitive iPhone/Android app limits usefulness of Wifi remote control.
• Resolution and video detail limited to 1080p at 24Mbps.

For my purposes, a Nikon full-frame DSLR fills a video niche that would otherwise require a Sony A7s: high-ISO low-light shooting. Neither the Panasonic GH4 nor the JVC LS300 produce acceptable noise levels above ISO 1600 (and even that requires Neat Video in post). Both of those cameras are otherwise excellent choices, with none of the above limitations of Nikon DSLRs. But for ISO 1600+ Nikon is a better choice, with a full-frame sensor and image stabilized lenses far superior to Panasonic OIS zooms. On the MFT side, the SpeedBooster option is indeed useful, but IME shooting video at effective apertures wider than f2.8 often produces a painfully narrow depth of field. I much prefer to shoot in low-light at f2.8 at a higher ISO.

With that context in mind, there's a video alternative I still prefer to the D750: a Nikon D800 with a Mosaic Engineering anti-aliasing filter, hacked to use a 64 Mbps bitrate. This combination of third-party enhancements eliminates video moire and captures the highest quality low-light shadow details of any DSLR short of the Sony A7s. (While the A7s is superb in low-light, its proprietary lens selection makes it impractical for my purposes.) Here are links to the third-party D800 developer sites:

Mosaic Engineering: http://www.mosaicengineering.com/products/vaf/d800.html

Nikon Hacker: https://nikonhacker.com/index.php?sid=1257e1f5cafd972a325cb7d868b55048

Of course, the D800 solution requires additional camera preparation and enthusiasm for custom firmware hacking. As one of the more prominent hackers of the GH2, that's not an issue for me, and I've tested Nikon Hacker's firmware upgrades to my complete satisfaction. IMO, 50Mbps is the minimum bitrate needed for fast-motion and low-light video shooting at 1080p. Unfortunately, the D750 doesn't meet that spec, and Nikon Hacker has been unable to increase the bitrates of Nikon models beyond the D800. For that reason alone, I must regretfully pass on Nikon's current generation of hybrid DSLR's, in spite their improvements in overall usability.

The following video samples show the difference 64Mbps can make in fast-motion videography on the D800. To clearly see the increase in video detail, I'd recommend examing the frames at 200% resolution in a video editor. The original footage can be downloaded from my Vimeo site.

Nikon D750 DSLR Camera, $1299

http://www.ebay.com/itm/201558664702

Nikon D750 Recommended Settings & Tips

Nikon D750 firmware version 1.11

• The WT-7 wireless transmitter is now supported.
• Fixed the following issues:
  • Incorrect histograms would be displayed for some images viewed in the RGB histogram display during playback.
  • If On was selected for Auto distortion control, distortion would appear at the edges of photos taken with NEF (RAW) + JPEG fine selected for Image quality and Medium selected for Image size.
  • The option chosen for Custom Setting f5 (Customize command dials) > Change main/sub in CUSTOM SETTINGS MENU group f (Controls) would not be saved when Save settings was selected for Save/load settings in the SETUP MENU.
  • Pictures would sometimes not be recorded.

http://downloadcenter.nikonimglib.com/en/download/fw/217.html

Is there a 30 minutes recording limit in EU version or is there more limited in all version like in d7100 for example to 20minutes?

Can someone tell me how to get sigma lenses focusing in "live view" at list hunting. It does not work at al in fact Autofocus menu is greyed out. On Nikon lens works. Is this Nikon competition way or what Im missing? it works on my d7100.

Thanks @ironfilm Ive got the camera already amd it is actually 10 minutes in 1080 50p

I did test other sigma lenses 135 f1.8 and 24-105 f4 both works well in live view AF. Older 50 f1.4 and 18-35 f1.8 does not work. Can anyone confirmed Id like to know if it is samething wrong with mine or user error. Thanks

New firmware version 1.12

• Added support for the following features of AF-P lenses:
  • If the standby timer expires after the camera has focused, the focus position will not change when the timer is reactivated. *In manual focus mode, the focus indicator in the viewfinder (or in live view, the focus point selected in the monitor) will flash to show that infinity or the minimum focus distance has been reached by rotating the focus ring.
• Fixed the following issues:
  • When pictures were viewed after shooting with Overflow selected for Role played by card in Slot 2 in the PHOTO SHOOTING MENU, the camera would sometimes display the second-last picture taken.
  • Microphone sensitivity would sometimes not be correctly adjusted when movies were recorded with Auto sensitivity > Microphone sensitivity.

http://downloadcenter.nikonimglib.com/en/download/fw/245.html

Nikon D750 DSLR Camera + stuff for $1296

https://www.bhphotovideo.com/c/product/1082599-REG/nikon_d750_dslr_camera_body.html

Nikon D750 refurbished for $1049

https://www.adorama.com/inkd750r.html