Most contest i don't use DX cluster, but i always use N1MM bandmap to spot the received / decoded / worked call-signs. It saves me time while sweeping bands.

When contest rules permit i use VE7CC cluster to fill N1MM bandmap. 

It's more of distraction for SSB, and not very accurate for CW/RTTY.

RBN is a great tool, and i use it to see where and how strong my signal is.