Currently there are some HEL—LHR 34 € Y OW tickets on BA (yesterday there were more availibility)

Additional pros for AY in C: Seafood special meal still available. Much better choice of timetable. Champagne in 1/4 bottles. The BA way is grand style but you need to ask for more more often. Fresh brewed quality green tea. As an OWE (BA Gold) I’m always asked for my preference of the two main dishes before the service starts. This happens even though I’m seated in the last row of C. And as it has been mentioned before it is an official policy to offer any drink free in Y for OWE’s (it happens on BA quite often).

Pros for BA: more Avios and cheese as part of the dessert. Peppermint tea. If the flight is not full a half row is reserved for BA Golds (often in Economy too)

I think I agree most of the other reasonings here.