[chemicalnovae]

More to the point then, is there anything that sits between the high quality generalist journals and generalist scientific magazines (Nat Geo. and the like)?

I can and do read Nature and Science, but outside of my PhD field I find it pretty slow going and often feel like I'm missing out on what could be interesting findings due to not having sufficient background to fully understand the problem space.

[anigbrowl]

Not that I'm aware of, sadly. There's New Scientist from the UK but that's more of a weekly newspaper and thus a bit shallow. There's some great online magazines of course (Quanta is pretty good) but for longform writing I still like hard copy cause I'm old.

[MayeulC]

I personally read Ars Technica (and am a subscriber), which I feel fills this niche (maybe that's not what you are looking for?)

Even though most of their articles are IT-oriented, they cover quite well major scientific publications in various domains.