You love to sleep on the mattress or on the floor?

Introduction
1

I have been doing yoga, and have long been accustomed to sleep without a mattress, but have not learned well to sleep, besides on a hard surface was not comfortable enough. But still decided to take the mattress, and don’t know what is right for me, whether to pay attention to such manuals and I still have to choose?

2

I want a mattress at any cost

3

I would like to sleep on a mattress rather than a floor.