Neu 1521 vs CC 1717

[Skelbow]

Just curious as to what everyone thinks about the two.

I currently have a 1521/1Y finned for my E-Revo, and have been hearing a bunch of stuff on this forum about the CC 1717.

So lets just say..

CC 1717 - 1580kv
CC 1520 - 1600kv
Neu 1521/1Y - 1577kv (the one I currently have)

All running on 5000MaH 6S in an E-Revo, which is best and why. Which would run the most efficient, have the most power?