I'm not the best drivers, I'm very tall, and have fairly large feet. I drove a manual 1925 Chevy. It's top speed is 25 miles and cruising speed is about 15 miles. The accelerator is between the clutch and the brake. I could not just depress the accelerator, I had angle my foot between the clutch and the brake, trapping it between them. This meant I could not brake quickly. The clutch and the brake are merely levers - no hydraulic assistance. Only the two rear wheels brake, it's braking distance is fairly long, even when you push it down hard. The steering is awfully unresponsive and as the car is top heavy, turning, even at its modest speeds, it felt very dodgy. At first I could not change the gears because my legs did not fit properly; nothing is adjustable except for the driver. No one else was game to drive it. In every way this car was slower, more dangerous, less stable and convienent than modern cars.
For a comparison, here's Aaron Swartz's review of a Segway.