Which retractable pen is similar to the Pilot G-Tec C4 in terms of producing thinner lines?

I love the Pilot G-Tec C4, as it is very smooth despite its sharp nib. The ink thickness is perfect for me; it's neither too thick nor too thin. But the only drawback is that it is not a retractable pen.

While researching pens, I came across several potential options.

1. Pentel Energel 0.3 or 0.4
   
2. Zebra Clip 0.3 or 0.4
   
3. Pilot G2 0.38

So could anyone help me decide which pen to purchase? Would appreciate any insights!