Which alternate upgrade for Inferno do you like the most?

You can increase the speed of the Archdevils! And if you're playing as Nibros, they'll definitely reach the archers! They usually don't make it to the archers, but you can pull the unit that's protecting the archers closer to you (for example, with Elves, it's usually Treants or their upgraded version), and then attack with Imps, Hellhounds, or any summoned creature that's closest! It's also good to use them against Humans and the Academy. For example, you can immediately pull Paladins or Lizard Riders towards you, so they can't spread out, and then attack them with Archdevils, Demons, Imps, etc. Basically, overwhelm them! IMHO.