Everyone's always talking about how shoddy it is and how your cabinets will disintegrate if they go through any kind of stress, but all my cheap-ass furniture with a piece or two missing is still going strong after nearly a decade a use. Maybe I'm just lucky and it really is all crap, but I can't shake the feeling that the reason people shit on Ikea is because it's inexpensive.
It's a great material for mockups and temporary whatsits, but if you need longevity or even transportability there's better stuff to be had. It just suffers too much from moisture and moving that you end up replacing it time and again.
Edit: thanks for the gold!