I can't really comment on the the vocalists for the two songs you've mentioned and I find it difficult to choose the vocalist that did the best job overall on the new album. What I can say is that I loved the new album right out of the gate and it keeps growing on me more and more.
It's interesting that Therion are planning a little different touring strategy this time around, perhaps not using choir. When I saw there here in Texas in 2005 the choir was one of the highlights of the whole show. I was fortunate enough to meet the most of the band after the show and Christofer indicated that, the way the tour was going and the expenses involved, he really didn't foresee Therion being able to tour the USA again anytime soon, especially in a headlining capacity. If true, what a shame that is because a Therion show is an event not to be missed! I for one hope they are able to return to the States in support of Gothic Kabbalah but only time will tell. Each time I think of quality, original bands like this struggling to make a go of it in this country I find my blood pressure rising when MTV, radio, and other media outlets insist upon forcefeeding us a load of musical garbage that can't hold a candle to Therion and telling us this is what we should like.
Thank God (or the deity of your choice) for ProgPower and festivals like that because we have precious few outlets for this kind of music and like-minded fans (at least that I am aware of)...