Are they better than regular carts? Is there something about having all four wheels turn-able that makes them better for schlepping furniture boxes around?
I was at IKEA yesterday, and those carts make me feel like I'll blow out a knee turning a corner if I'm not careful.
They're impossible to slow down when turning, they sometimes don't turn all the way, and you feel like you're going to crash into a shelf (or wall), but at a 45-degree angle instead of head-on.
They're curious creations, and it's my least favorite part of IKEA. The trick is to walk beside them to eliminate the lateral swing, but it's still not a fun experience.