Like the Leganza, the Nubira's engine is buzzy when it gets over 4,000 rpm. I also discovered that I didn't have to drive it over 4,000 rpm, and had I driven the Leganza with more intelligence, I probably would have kept its tachometer in the smaller numbers as well. With the Nubira, for example, you can reach speeds of 60-70 mph on the highway and still keep the engine in the quiet zone, and this is a nice operating range for the engine. It's only when you're under hard acceleration or kicking in the loud pedal to try to pass someone that the noise comes on. Part of the reason for the noise is that the engine is connected to a four-speed automatic gearbox.
Automatics are notorious for making the engine work a little harder.
With a manual you can better regulate the power. That's one reason fuel economy is better with a manual than an automatic. That's also why you're probably better of fin the long run with a stick shift, even though the benefits of automatics make them more desirable. Front passengers sit in leather-upholstered individual bucket seats. They don't offer much side support, but in a compact sedan you're usually not looking for that kind of support.