Other than bowl capacity, transmission type is another important consideration when selecting a floor mixer. Most are either belt or gear driven, and each type has its advantages and disadvantages. Belt-driven models tend to have variable speeds, so you can easily transition to a higher beater speed and reduce product splashing. However, belts can wear out over time and will have to be replaced.
Gear-driven transmissions should never wear out and have to be replaced because the gear housings are usually permanently sealed and have the sufficient amount of grease to keep things functioning properly. One drawback is that gear drives tend to have fixed speeds, and there is always that small jolt or splash of product when switching to a higher gear. The manufacturers often argue that these units are stronger, but that is debatable.