Hi there,
I have both types of bikes,. My flatbar is a Specialized Sirrus, which has road tires (700cx28). I bought it last year when I first got back into riding.
I also have a Specialized Dolce, for a drop bar road bike. I ride about 100 miles per week, or more, and have grown to love the drop bars. I do have the cheater brakes, which are a second set of brake levers mounted on the top of the bar, in the flat section. You don't have to go into the drops to brake, which is nice.
I switched to the drop bar because I don't have the finger strength to shift with the thumb shifter on the Sirrus. For whatever reason, the shifters on my Dolce are easier for me to use. But, the Sirrus has disc brakes, which I am wild about.
So, every decision is personal. As for me, the Dolce is for long road rides. the Sirrus for wekend jaunts on the paved trails....
If you've been riding a hybrid, you might like a flat bar road bike to start with. You get the speed, without having to deak with the dropped position.
Hope that helps.
Wendy