What are they like for riding on the hoods?
Not that great, I have mine set so the flat of the drops is not quite horizontal, but at 90degrees to my arms, if that makes sense. with the brakes set so they’re comfy to reach in the drops, the hoods are a bit of stretch down and out.
Are they mainly designed for riding in the drops?
yes. as above, and there’s less drop from the stem, so they’re comfier for longer.
Any benefits over traditional drop bars?
Bit wider and flarey. I got them for a bit more control off road, and I quite like the position on road, but sometimes I’d like a few more positions (hoods, and more space in the crook of the bend for when you really want to get out the wind) Probably not enough to swap ehtm out though. unless I start doing some very long rides.