I have to be careful here...my opinions, these are not facts.
Okay, I will compare the 8m. Low end about the same, maybe the cat a tad lower. A knot lower. Top end no competition, the cat didn't like its top end much, got real punchy. Anywhere over 25 was a mind fck. Especially if gusty conditions. Its like the C in it was magnified! Dice hold its form and handles gusts much better. Been out in 30 knots and could have gone more.
Power, considerably smoother on the dice. Cat higher bar pressure, delay in turning, then wham you'd get a power spike across the window. Dice comes on smooth and linear. Will the cat turn when depowered, no. Does it drift, kind of not really. Maybe some. Does the dice do all these, yes. Apparent wind build up...mmm similar, dice flies a little more forward in the window at first, then settles back.
Jumping, mmm similar. More float on the dice though. I can get higher on the dice though, the power delivery is so linear you can really dial in the load and release. But the cat can go.
Did I like the cat? in the end, no. Is this the reason i went to the dice? yes. do i think ozone have it wrong having such a gap between the cat (a pretend C4) and the full blown race kite?, yes. do most disagree with me,? yes. do i care? no, becuase otherwise i wouldnt have tried the dice.
Hence these opinions are biased and so take no notice whatsoever.

Look the dice is not the holy grail of kites, its just a bloody great wing that suites where I'm at at the moment. I still dearly miss my edge for power, height and glide. But those days are over.
So get out there and fly them all and don't listen to flog bags like me and all the other pricks banging on about kites. Use your own time like I did and find out what suites you at this point in time. Also open your mind to different brands, most make bloody great kites with specific feels. Find the right one for you.