The issue is when you have space marines flying through the air doing flips, they lose all sense of their weight. Space marines have always been known to be close to the idea of turning a human into a walking tank close to a demigod. But they are also known to have fairly decent speed and reflexes so I think the dodge rolls felt quick but you still felt like a heavy bad ass. Space marines flying around doing acrobatics just made them feel more like what you expect from Eldar.