Inferno is a 20th-century update of Dante. The Prodigals wear Gucci. The Simonists advertise cheap Th.D diplomas. The guards on the River of Blood carry AK-47s. The guys who ordered the firebombing of Dresden are with the Evil Counsellors. It's a very disturbing, very clever, very thoughtful, and VERY depressing work, but it does provide an explanation of why there has to be a Hell at all. I mean, yes, people did bad stuff when they were alive, but it ends. Why torture them for all eternity for something they did in a life that didn't last more than a few decades, tops? Where's the justice?
Given how depressing Inferno was for them to write, I can't believe they went back in Escape from Hell. They must have had something important to say. Should be good.