I have a bike with drop and one with flat bars.
Drop bars are set up so that on the hoods, I'm more upright (bar top is just below seat level), so I can see above cars. Also, the STI levers are set up so that I can brake well when on the hoods. When not in slow traffic, I'm always on the drops - just made sure I keep a finger or two on the brake levers.
The only flaw of drop bars i the availability of levers - regular, bar end, or STIs are all very hard to find in my country. Also the price. That's why I keep an old MTB as a backup ride.
MTB is a no suspension steel one. It is better for shorter distances in crowded, heavy traffic. More nimble, easier to manouver. Drop bar bike is better for distances over 5 km one way.