This guide will give you the basic differences and advantages of each type of 2 post car hoist.
Base type 2 post car hoist
Clear floor 2 post car hoist
Like the base type car hoist the clear floor is usually driven by twin hydraulic rams. The more advanced and modern clear floor hoists have full length direct drive rams, where the carriage is directly attached to the ram. The big advantage to direct drive style is there are less moving parts, no chains, no pulleys so less maintenance and smoother operation. Clear floor car hoists are the most popular and are most common in workshops. The reason being that the equalising cables and hydraulic hoses are carried overhead rather than across the floor. Giving you a "clear floor" to work with, hence the name. You can use a clear floor hoist for all the things you can a base type plus transmissions, gearboxes, restoring old cars and anything other type of work where a jack would be used to maneuver components from the front to back of vehicle.
Ensure that whatever hoist you choose has Work Cover Design Registration and complies with AS1418.9.