I have had both but for me the invasion handles more oil and carrys much better, and the mutant was more angular and rolled much better. The Mutant just simply didnt carry. Granted the mutant is at 2000 grit, and the Invasion is 4000 grit. It would depend upon how much equipment you actually use, if you only use 3-4 balls you may see some overlap, but if you have 10 or so it would be a great piece to acquire to give you a different look when you need it. I have too much equipment and bowl around so nothing really overlaps because i see a different characteristic from each ball house to house. If you bowl on a heavier patterns go with the invasion, otherwise the mutant is pretty much a beefier orignal cell IMO.