Who is the Brahma for? Probably for someone heavier than I, someone looking for a narrower ski that is a less technical ski, primarily for off-piste conditions. Who is the 8.5ti for? Someone at least as heavy as I (although heavier skiers can use it), someone who wants a more technical all-mountain ski that can handle anything, but is still a very good carver.
With how I ski, I don't want to make too many groomer compromises with a sub 90mm ski. It needs to be able to ski anything, but hold it's own on hard snow (and by that, I mean energy, rebound, fun factor: not just grip. Too many people equate hard snow performance with grip only; for me, it is more about "how fun is this ski"? Getting a ski to hold on firm snow is easy. I love the Soul Rider on firmer snow: it is just a blast, and in some video shots, the skis are clear of the snow on each and ever turn exit. That is the definition of a "fun" ski, even though it isn't really a groomer ski. It still skis like one).
I have never skied on the EC. I do like the 8.5ti for how I ski though: it is a technically oriented, powerful all-mountain ski. The Brahma, while fun, it not technically oriented: you lose a lot of the tip and tail on hard snow, the top of the turn is neutered, and I feel the flex is tougher for me to handle in the bumps (although the latter is strictly a weight issue; I am pretty light and the 8.5ti has a bit better flex pattern for me). The tip on the 8.5ti inspires confidence on crappy groomers in bad light. The Brahma for me is a narrower off-piste ski (I would probably use my Kabookie if skiing Blizzard for those conditions) so it is a ski w/o a home in my quiver. The 8.5ti is a more powerful, more fun ski on firmer snow, while doing just as well in off-piste conditions. The downside is that the speed limit is lower in junk snow than on the Brahma; that Brahma is pretty beefy and you can run at serious speed, just like the Bonafide.
For me, if I am going to ski something in the mid 80's up to mid 90's, I want something that is very good technically but can still rip bumps and variable off-piste conditions. My off-piste ski is going to be typically wider than 88mm underfoot, more for soft snow. I could split those and run the Brahma, but I find the 8.5ti/Kabookie type quiver to be more of the ticket on how I ski; no compromises really for either end of the spectrum. If I skied a place that gets a lot of snow at once (I don't really), then I would probably opt for an 8.5ti/Scout quiver if staying with Blizzard.
I say try both and see what you like. There is really no right answer. A lot of people would tell you they prefer the Brahma for frontside skiing, meshes with their skiing style better. Great that we have options!