I currently use sdf op[. I used to use sdf kl; because jkl had ghosting issues.
Like SednA said, there is no right key setting. Find what works best for you. The thing is: you shouldnt even be worrying about your key choices yet. Key choice is a minor thing until you get much better.
The switch to the upper row on my right hand made a difference for me, but that was because I identified a problem (my left hand had better stamina) and I tested a change based on looking at how I physically held my hands over the kb and realized my right hand was more curled than my left because I had to hold my right hand higher on the kb to hit the space bar. I decided to increase the distance between my fingers and the spacebar by moving to the top row which let my fingers hit the keys on a lower angle rather than being curled downwards. This made a small but noticeable difference in my right hand's stamina. But I only made this change after playing mania for years with both hands on the same row.