Anyone who posts some "in the olden days" post is just trolling, there are 12 fights in a series, comparing xpac to xpac some will be up some will be down in difficulty and/or enjoyment. On the whole, across the 12, these raids are approximately the same as Eden and Omega (I guess you could argue that the Omega series was a bit simpler). None of the 3 most recent xpacs have been gigantic departures from one another difficulty-wise.