I spent about 30 minutes the first try but I didn’t know the ritual myths and especially secret handshakes. Another 45 minutes the next day and finally magic! Then I tried to change the USB password and oops! Finally I got SnapBridge connected a second time.
Yeah, Snapbridge can be tricky to connect sometimes. If there is a lot of radio interference e.g. when in the vicinity of my home wifi router, or in big public events with large numbers of cell phones around, it might not connect. But usually, when in absence of such disturbances its recent versions connect reasonably painlessly and then you can transfer images to the world without a computer.
I find the D6 version to work somewhat more fluidly (I assume it is similar with Z6, Z7 and other newer cameras) and it also allows wifi transfer to computer (using Nikon Wireless Transfer Utility) which is more reliable and "sticky" than using the built-in wifi to connect to a smartphone (with smart devices, Snapbridge is sticky when using bluetooth but the wifi connection is easily dropped which is a bit annoying). The technology started as really finicky and erratic but it is gradually improving and I think in 5 years many people might not remember that there ever was a problem using it.
SnapBridge is fun but what’s it really good for? Social media? Uploading photos for eBay? I think it’s transferring GPS location data to my camera but I’ve always been in the same location so I'm not sure. My camera is a Nikon D850.
It does transmit GPS location data from the phone once the bluetooth connection is turned on. I use Snapbridge to transfer small jpgs to my friends when photographing if I have an interesting image that I'm excited to share, I'll use it.
What options are members finding for serious preview of full resolution JPG(s) on a laptop or desktop computer with low latency? Which option: USB or WiFi? What is available in standalone Windows and MAC programs?
I have connect to camera or dslrdashboard (same app, different names) which can be used to use a laptop or desktop (as well as mobile devices) to transfer files. However, whether the latency is low is debatable. You may need to use more basic JPG settings to get fast transfer of images wirelessly than you're used to when using USB cable or memory card reader.
On the D6 (I believe also Z6, Z7 etc.), also the camera itself can transfer images to laptop or desktop (using the WTU software that Nikon makes downloadable for free). This is really fast for basic jpgs but a bit slower for fine quality jpgs or raws. The JPG quality setting makes a huge difference to transfer times.
If you need high speed transfer of large fine quality jpgs then you may want to use a USB cable (or ethernet cable in the case of D6) to do it. This is much faster than the built-in wireless capabilities but I personally hate tethering with a cable (for safety reasons).
What options are available for serious remote camera control? Especially important is pre-focus in live view with low latency shutter release. Having the camera focus in live view before releasing the shutter is not useful for many applications.
I have three options for that: the connect to camera / dslrdashboard application, Nikon's own Camera Control Pro 2, and Manfrotto Digital Director (which is like an iPad adapter using USB cord and a mount). However, I rarely use them.