i've done it a couple of times so that i could combine everyone's points, and then have just transferred what we need then into my account, and have put in for everybody's business upgrade out of the one account, being mine. i just find it easier dealing with MH that way sometimes.
just remember to check that your economy fare is in an upgradeable class before you book it. i semi-book it over the internet, and then ring MH and ask them whether there upgradeable seats available for that flight that i want. i have been known to change flights before, as they will tell you what's available.
they are very good over the phone i have found, and i haven't ever had a knockback on my upgrade requests.
MH Business class is very good.
The Lounge in Sydney is simple but good, better than sitting out with the masses, and the Lounge in KL is fantastic.