The Nikon manuals give a chart of nominal file size given the three resolution and three sizes Large....Basic, etc.
Yes I'm talking nominal file size vs. IQ - another way to ask the question would be "is there any detectable difference, given same size prints, from a high pixel count sensor that has been used to make a small basic jpg vs. a camera with a low pixel count sensor running at Large / Fine" where the jpg file sizes are about same.
Or even simpler, do I need a D5 to make the very best jpgs for the web ?
I think I know the answer but never seen such a test run by those who write photo articles.
Well, Large, Medium and Small are image sizes, different numbers of pixels.
Fine, Normal, and Basic are JPG Quality parameters, which does not change pixel count, but which offers a lower image quality.
Both can reduce file size, in different ways. Image quality and resolution are not the same properties.
So Large and Basic are not on the same concept scale.
Camera default is Large Fine.
If concerned with better image quality, there would seem to be no question about it, select Fine. If concerned about quality, why would you want less quality? Is file size that important? Disks and cards are inexpensive compared to the camera, or even lenses. Would you want to instead see your alternative result choices before forcing that choice?
If concerned with image size, then 24 mp sizes are:
Large 6000x4000
Medium 4496x3000
Small 2992x2000
Now if you are always going to resample even smaller to view on a 1920x1080 monitor screen, or if going to print a 6x4 inch print at 1800x1200 pixels, then I frankly doubt it will make much difference which size you start from. However, the larger size can offer larger prints with greater resolution, and also offers greatly more choice about cropping some of it away, and still having sufficient pixels for your purpose.
And we don't always realize when our next picture will be the keeper of a lifetime...
I would suggest always Large Fine (because there is no going back later), and then when and if you must have a smaller file, simply handle it later. Maybe save and archive the original first.