When we had our first, we didn't have a changing table but my wife didn't even use a changing pad on the floor! I thought this was gross. Three kids later, I still do changes on the floor and rarely bother to use a mat unless I can tell it was a blowout. Even then I'm more likely to just use the bathroom floor and wipe it afterwards, rather than having to clean another surface--because let's be honest, it doesn't always stay on the mat. Absent blowout conditions, as long as the baby isn't too wiggly the diaper just acts as its own barrier. Now if I were really going for self-preservation I'd have not only a mat, but a hazmat suit and goggles, but life is all about compromises.