I finished the last arc of the first season of Index, and while at first I wasn't expecting much from Hyouka's story, in the end I give them props for taking what I thought was going to be just another generic meek/shy bishoujo, like an anti-Biri-Biri, and making her into a badass. They did a good job developing her character and building the friendship between her and Index - it's hard to throw a character into a series a couple episodes before the end and expect the viewer to care what happens to them, but I think given the time they had to work with, they did a good job with it.
The series ends with some hints of the next story arc, possibly to take Index and Touma out of the familiar environs of Academy City - but now October and Index's second season seems like a long way away. To get my fix, I might have to squeeze in a re-watch of Railgun between now and then (the first 12 episodes anyway...for me, at least, the second half of Railgun was kind of a letdown compared to the first.) There are probably a few more cameos I missed the first time I watched Railgun, like the idol Saten-san's listening to in the first episode, that I didn't know were references back to Index, since I watched Railgun before Index.
Overall I'm glad I picked Index back up - I'm not sure why I dropped it the first time it was airing, but looking back I didn't give it enough of a chance, since it's been fun to watch this time. Between Touma, Index, Biri-Biri, and Kuroko, I like the cast enough I could happily watch a dozen seasons of this. Throw in some epic battles, an intriguing plot, and good animation quality, and it more than makes up for some of the longer-than-necessary dialogue in the first few episodes of the series in my book.