[obermd]

I have driven GM cars with both disc/drum and disc/disc setups. The disc/disc setups handle multiple, repeated stops better than disc/drums. Disc/drums catch quicker when wet. For a single emergency stop either will do just fine. I have made emergency stops with both setups, including in my ECO MT. This car will stop on a dime compared to most other cars on the road. So unless you're towing or carrying heavy loads the disc/drum configuration on the ECO and lower trims is more than sufficient.

Drum brakes are cheaper - thus the reason to use them.

 

[obermd]

To add to what you said, the drums function very well for a single emergency stop. If you need to make constant, repeated emergency stops, you have a problem bigger than your brakes.

There are some mountain roads in the county I live in that will give disc/drum combinations a really hard time, even without emergency stopping. These roads are steep, low speed, and with a large number of very sharp switchbacks. On one of these roads my Pontiac Transport (disc/drum) would always come out of the canyon sans brakes. It would take about half a mile for the brakes to start working again. On the other hand my Pontiac Montana towing a 3,000 lb trailer never had problems. I haven't taken my Cruze on this road yet so I don't know how the disc/drums it has will fare. I suspect it will be more like my Montana because of the manual transmission.

 

[obermd]

I've come down Pikes Peak in a manual transmission without even warming up my brakes. The speeds on the particular road I've had problems on are at most 3rd gear and most of it is 2nd gear. Even the ECO MT has good engine braking in 2nd.