I've attempted to read Dante's Inferno at least twice before, years ago. I stopped not because I wasn't interested but because I felt intimidated. Robert Pinsky's translation has made all the difference; this was not a painful read at all--excluding the horrific and grotesque depictions of hell themselves. Pinsky's translation was all the rage when it came out and through my years as an undergrad (at least in poetry circles), and I can see why. It's lucid and captures something of the original terza rima in English: no easy feat.
I'm also smarter about how to read works with copious notes. I simply read a canto THEN flipped to the back and read the notes. The cantos are short enough where this makes sense, and I could understand the narrative for that period.
As for Dante's work, it's still awe-inspiring as a literary accomplishment and as a text that is inextricably a part of culture. It's essential reading for poets and writers, or artists, period--the journey through hell is a common theme of artistic maturity in part because of Dante. It's a portrait of mentorship, not just of hell. As a narrative it's also compelling for its use of point of view--Dante the poet writing about his journey after the fact and Dante as pilgrim traveling hell with his guide, Virgil.
Much of the imagery in the Inferno is still shocking, though in a few places it's also darkly comic. I read a canto each morning as I ate breakfast, which was not always the best idea! The tortures Dante invents are graphically depicted so that, like Dante, you can't help but pity the sinners at times. Some figures come from history and mythology, while others, though real people, are not known unless one is familiar with Italian history specifically--naturally, the shades Dante wishes to talk to are those he knew or knew of.
As an atheist, I could only connect so much with the story, or only in the way I might when reading fantasy. The human elements are what matter to me, not the baffling construct of hell (baffling in which sins are considered worse than others and why) or the condemnation of those who simply happened to live before Christ, were not baptized, were homosexual, or were "heretics" (i.e. anyone not Christian) or "usurers" (typically code for Jewish).
What would the nine circles be and who would be in them if Dante were writing today?