Thanks for all the input!

I don't mind the Embraers too much having used them a lot in the US... 2.5 hours is a long time to be on one but probably better than driving to Heathrow and starting the journey from there.

The business class service sounds decent enough. I am in the A340 on both the long-haul AY segments - no MD11 which I am very grateful for.

I guess given the itin is (probably) a lot cheaper than going BA/QF all the way, and will get more tier points than the straight-through BA flight (also netting 40 each way for MAN-HEL) it's probably a good choice.

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.