Tub floor boats are less expensive but may restrict where you take your craft. Drop-stitch floors are flat, allowing the boat to slide over rocks, spin and draw sideways easier. Flat floors also tend to be better in tight, technical water and make it easier to rig gear and install foot cups. I-Beam floors feature parallel ridges, are less expensive and improve tracking. Consider whether the floor is glued or laced-in.
Glued floors offer a little more room for passengers and gear.
Laced-in floors are more expensive, drain faster and are easier to take out if they need repair. In some cases simply a measure of elbowroom. This varies by size of the craft and between manufacturers' styles. Coating determines the boat's air retention and abrasion and UV resistance, and a boat's material is usually referred to by its coating. Base fabric is usually nylon or polyester and determines tear strength and puncture resistance.