I haven't drive both of them but I have travel on the Space Wagon(Chariot) 2.4. First thing I want to say is, the price of that Space Wagon is way too high, I think it worth 25,000( if u are talking about the 2.0 not the 2.4, even the 2.4 is expensive, 45000 to 50000 should get u a nice one.) The power on 2.0 is enough for u to use but no more, but well, MPV is not the kind of car u want to drive fast. I guess the Dion is using the GDI turbo engine, so instead of 2k cc, u found a 1.8k cc one. U have to look out for the GDI because it is quite sensitive to fuel quality, and the oil pump is known to give trouble to the owner. If u talk about the space, I think is about the same (if u are talking about the 2.0 space wagon, if not the 2.4 is bigger and have a 6 seat captain seat version.) The build quality is better on Dion. (But the 2.4 space wagon version is better)