Which of these two ships would you choose in a Rebel Alliance 4 ship list?

Kullbee Sperado (48)
R4 Astromech (2)
Servomotor S-Foils (0)

Total: 50

or

Norra Wexley (Y-Wing) (41)
Ion Cannon Turret (4)
Ion Torpedoes (6)

Total: 51

No context given, as I am really interested which of these two ships (and their particular loadout) you find more useful and/or stronger in general?

I think Norra is the better ship overall but most X-Wing pilots are pretty good. That being said, context is pretty important here. The choice between these two comes down to their specific role in your list and what gap they’re filling.

If you go with Nora then add Veteran Turret Gunner to give a bonus attack.

Norra, no contest. She is a beast. Drop torps for gunner or afterburners though

NORRA

I'd probably say Norra Wexley.

I'd very much recommend Afterburners and/or Expert Handling, though - her pilot ability is awesome but demands the sort of fine control over your final position an un-upgraded Y-wing struggles to deliver.

norra but change the torps to VTG

Given no context and only these exact load outs I think Kullbee is the better use of 50 points.

As others have pointed out above though, this is a very apples to oranges comparison and for that matter this Norra is not a particularly ripe orange...