I have elite gravel aero+ wheels with 32 internal and 40 external.
Around 3k km put into them already, so far, flawless. I ride everything from road to mtb single tracks, survived even Santa Val stage one, sadly seatpost broke on stage 2 lol. After all these kilometers they are still straight as new.
50mm schwalbe g one rx pro tyres blow up to 53mm on them, so be careful if you're riding on clearance limits of your frame.
Can't really comment on any downsides as I didn't find them yet, they are light and stiff.