my gains are the same no matter the arms, motors, usually 140-140-120-130 and anywhere between 80-80 and 100-100....... where ever self leveling interaction and i quit knocking heads.
Never seen any resonance, only thing i've witnessed is it can be over propped... at which point becomes extremely unstable
Theres two sweet spots i've hit so far but were bringing in some u series tigers to check through those. the tiger/amp 3515 500kv on 12" without load, 13-14" with load and the standard length arm kit with 2814 and 900-1000kv on 9-10" props..... with the 900-1000kv we run the zippy compact 4s 5000mah packs, on the 3515 we run the zippy compact 6s 2700 mah.....
U5 look promissing, bigger better bearings, more power than 3520 but alot more efficient
These arm kits with the big motors/props have an unbelievable amount of yaw authority if that's what your asking, guessing that's the momentum ?