Flew STN - EWR - STN with Primera on 321 (PAF) both ways.
Had booked row 9, even with child passenger. Confusion at check in on outbound, but allowed to sit there by crew. Only 6 or so spare seats dotted throughout cabin. Premium full.
On return, aircraft full, agent wouldn’t allocate us our paid for seats as they’d already been assigned to other passengers. They then upgraded us to premium seats (seat only).
On time, safe and clean.
We will use them again.