His reasoning being because it has a surface mount motherboard.
TBH I can see what he's getting at, compared to earlier big boxes the A4000 was more technically advanced, but physically it wasn't so well finished (thinner metal, cheaper plastic moulding on the front, plastic memory clips etc).
Obviously this doesn't matter to most people, who are more concerned about the machines capabilities, but it does to Doomy.
As for me, I love my A3000 as it is, but if I had an A4000 I'd want to put it in a nicer case (though that'd be plenty enough for me).