One thing - what's the best lounge to head for in HKG? If the one Finnair business lounge is the same one I accessed flying Dragonair J 18 months ago, then I am sure my OW Sapphire can get me in someone better.
Ive flown LHR-HEL a few times on their A320/319 aircraft with both the old seating and the new seating. The old seats were far better, its now 3 seats on each side with one isle. The food and service is outstanding, better than BA in my opinion. I believe the seats on the A340 are the same as LH, in which case they can be manually overridden to go flat, its still no CW bed though.
Others will correct me if i am wrong, but BA Silver card might not let you get your full pick of the lounges in HKG.
Finally, it was a good point about the security queues at HEL. Perhaps that is why it is appropriately called...