Tier 9 only with 20mm. 30mm heat fast and accuracy is off for me. 30mm are good only at the end of battle against GAA.
20mm configuration has good maneuverability and enough fire power against lights and multiroles. I will say mediocre.
Tier 10 need love. I like it when RoF was not an issue just before the nerf.
Agreed, I'm comfortable with the 20mm on TA183 but 30mm, hell no! it's accuracy is even worse than those on me262..