Might want to check a few searches here because I think I've read the XT32 implementation in the 818 is "crippled" as in it does not include the full sub EQ component? I could be wrong on this. Just a friendly heads up.
FWIW, I've used an onkyo 905 (with XT) with the antimode S-II and it does not sound as good as my 5009 with XT32 alone. I haven't run any graphs, just my opinion.
I will most likely sell mine soon.