Oops! Sorry, JetBoy. I meant HEL, not ARN. If memory serves, there are at least two Finnair lounges at HEL, and both are equally busy. The transit time between the transatlantic and the Europen flight would probably be in the AM, so hopefully the congestion would not be too bad.
I don't recall seeing an updated business class on Finnair, but it has been a year since I flew them transatlantic.