finding a really good Fr7f/z will take some hunting. I have a regular fr7 and its nice but not fantastic. I’m not afraid of vintage carts but you cannot ignore that they are old...
Regular FR-7 and FR-7fz is day and night difference.
I have compered these two FR-7f & FR-7fz versions and "fz" is much better.
This particular series (if the stylus is not worn) is the best investment because sealed suspension never fails. No one never seen any FR-7 sample with weak suspension/damper. This is just a proper design by Ikeda-San. Loads of fans here on audiogon.
Another killer Japanese LOMC is Miyabi Standard and Miyabi MCA from Takeda (Legendary cartridge designer).
Those vintage MC cartridges are pure magic!
Fidelity-Research FR-64fx tonearm with stock counterweight is not heavy, but with this optional W-250 counterweight (double size) and heavier headshell (or over 30g SPU alike cartridges) is heavy. The 64s is heavier by default, because the armtube alone is heavier, but two counterweight cab be used for different cartridges.