Raw JPEG worth the space?

I would argue no, there isn't, especially as Aperture can create a jpeg preview automatically on import. This mode does have its uses, and sometimes media shooters do this to have a jpeg to send immediately back to the office. Other than that, I'm not sure I see the value. YMMV

+1 and well said, fwiw. Really comes down to your (the OP's) needs. Those who need the JPG, know they need the JPG. If you don't know you need it, you don't need it.

OTOH, if you are satisfied with the JPG, you don't need the RAW.

My pfennigs.

For my first test, I set my camera to Raw + JPEG. This mostly looks like a nuisance, since it wastes space and time. And I have to look at every image twice. So it's a brain waste too. :-)

But is there any value to keeping the JPEGS?

First of all, if you already imported RAW & JPEG pairs, the question is moot, since there is no safe way to remove the JPEGs from the pair other than exporting the RAW riginals, then deleting the pair, and reimporting the RAW original file - a lot of work.

RAW & JPEG pairs are useful, if you are satisfied by the raw developement done in your camera and are happy with most of the JPEGs, but want to keep the RAW originals just in case there are a few JPEGS that you rather would like to adjust directly from the RAW in Aperture.

In that case the best strategy would be to import the JPEGs first, identify the images where you rather would use the RAW files, and then import the raw for hese images only.

But if you want to develope all images directly from the RAW yourself, then the JPEGs are really redundant.

or I need to upload somewhere unusual

In that scenario you create a Jpeg version from the Raw with Aperture.