I'd have to disagree. The explanations are even more tedious in the novels since you have to read them and the story often gets bogged down by them. An excellent example of this would be the Daihaseisai arc, where we had extremely lengthy explanations about how magic works and such that weren't really needed, and the anime made it better by cutting them out all together. That said, I do agree that Index is a best seller partly because of those lengthy explanations, which are very fascinating. Either way, it's not that much of a consequence to Index as an anime either, since the BD/DVDs still sale very well.
And yeah, if nothing else I'm looking forward to seeing the animation for this OP. Unlike No buts! it doesn't have a high tempo all the way through, so I'm anticipating less fast paced pans and something more akin to the first season's OPs.