Mostly hoods.

Drops on downhills and fast curves. Mostly for better control and emergency braking (lots of deer and other critters where I ride).

Tops with hands near the stem on slow grinding climbs, especially into the wind.

I've tried the theory that the hoods are as aero as the drops, maybe more so, when keeping the forearms as parallel as possible to the ground. Seems to work. So I use that on flats and moderate downhills into the wind too. Easier on my back and neck too. At 61 with several old back and neck injuries, it's more comfortable and still reasonably aero. Works even better with the more ergonomically friendly handlebars and extended hoods/grips.

I spend about 1% of my time on the drops. The rest of the time is split on the tops, bends and hoods, moving my hands around frequently. I was thinking about this the other day while riding and thought that I should be riding my bike that has bullhorn bars more.

Hoods on my Trek 75%, drops 25%,, and on my old Fuji drops 100% - no hoods and closer to the shift lever.

53% Drops
35% Forearms on ramps (similar to TT position)
7% Misc., tops, no-handed
5% Hoods
:D

That's the BIG advantage of drop bars--hand positions are infnite.
Jon

My single speed has bullhorns. Trust me, you'll miss them that 1% of the time.

90% hoods. On my vintage bikes, the brakes aren't very effective from the hoods, and the drops aren't as deep, so I spend more time in the drops. My old Raleigh, built from a found frame and a buffet of used parts is my most comfortable bike in the drops. Feels like it was custom made for me. I'm still trying to dial in my Peugeot. It feels better on the hoods, but the Mafac brakes don't feel too effictive from the hoods, so I'm trying to get into the drops more. The Peogeot has a wierd slope from the horizontal to the bend, so the standard bars aren't as easy to deal with.
https://cimg8.ibsrv.net/gimg/bikefor...14c7a85051.jpg
When the tops and hoods feel right, the horizontal drops are angled down too much.

https://cimg8.ibsrv.net/gimg/bikefor...f573d1dafc.jpg
The Raleigh is just right on hoods or drops,

+1