The nozzle check pattern definitely represents a non-delivered droplet, Mark. Whether that's because of a blockage, lack of ink (air buble, although very unlikely), failure of the head to fire, or some other reason will obviously vary, but it's definitely due to a droplet not being delivered to the media.
It's also important to remember that this corner of the web is photographers, which does not represent the largest portion of large format printer users in the market for *any* of the manufacturers (particularly not for HP and Epson), so any statistical analysis of "complaints" here isn't representative.
Ink usage, though, is a bit like pixel peeping. When I drive my car, I can get instantaneous fuel consumption data that is accurate to the second, but what I really want to know is my average over longer distances in different conditions because the instantaeous data from range from 0.0l/100km to over 40.0l/100km depending on if I'm coasting or if I've slammed the accelerator down from the start, whether on a hill up or down, so and so on. In the same way, what you really want to know, is how many prints you can get from a set of cartridges and, if you do have wastage from bad prints, the frequency and cost of that as a percentage overall.
If you look at the proofing market, which makes ink and printer usage in the photo market look small, then that is a reasonable guide to reliability and consistency. Some of these users check colour multiple times a day, or even with every print (FOGRA for example).
By comparison, I have printers that don't get used for weeks or even months and then do a few prints or do dozens. Most pro photogs would be some where in between.
One technology masks the issue (not in a devious or bad way, just a different technology) and one doesn't, but instantaneous results are far less useful than long term ones.