As far as this "Disney will not build any new rides in WDW if people on TPI don't vote for the Disney Sea rides" is just plain wrong. I am not saying some people at Disney don't look at this site every once in a while but I can just about promise you that none of them are deciding what ride to build or not build at WDW based on a fun tournament on TPI.
It also helps that Disneyland's Haunted Mansion holiday is my single favorite Disney attraction, even if the regular version only ranks somewhere in the middle of Disneyland's E-tickets for me.
Also, When you blast out of the volcano, it's my understanding (I could be wrong) that you see Mysterious Island, keeping the theme better than Any mansion on this earth (May may change that...).
Haunted Mansion is great, it really is, but I don't see how it's a better overall attraction than Journey to the Center of the Earth.