In an expansion mindset, the A380 would certainly be a better fit as the 748 would only fit a handful seats more than the current jumbo, especially if they decide to go for premium eco and to drop the coffin class.
Not to mention that as competitors are receiving theirs, it won't be long before they all start sending herds of 'em to HK, and since it's pretty popular with the punters, our dearly beloved premium pax won't be long in asking why they've just spent a ton of money to fly in a 40 years old jumbo while they could've gotten an A380 for the same price with BA, AF, LH, QF, SQ, KE, even EK...
On the downside, it would be harder to send it on regional flights the way the 744s are used today. I doubt MNL is in any way ready to handle one of these, much less DPS...
And the way EK is ordering them like they're running out of fashion, it might be tough to get early slots, especially if they don't sort out the production rate issue.