I got to try out the infernal-pact hexblade as part of D&D Encounters tonight, which was a blast for two reasons; the first is that I was the only person in the general area aside from Shazbot that had a copy of Heroes of the Forgotten Kingdoms, but the second is that I like being able to conjure up a hellish sword of dark energy that deals 14 damage on average. Reminds me of the end of Scott Pilgrim vs. The World.
It was the grand finale of Chapter 1, which had us stumble into a clearing while searching for someone. I don't recall the exact plot behind the encounter because the store owner was doing it on the fly and hadn't really read up on things. All I know is that it was a storm warpriest, dwarf slayer, and me up against a trio of lizardfolk, dragonborn, and "crazy guy". Despite having a new guy and being outnumbered, we kicked all kinds of ass.
Unfortunately, it was only one encounter so I can't say for certain how well the class holds up in the long term, but its a solid concept that I wholly endorse. The hit points and damage output are superb, and the Armor Class ain't too shabby. Having Charisma and Constitution as two key stats (go tiefling racial mods!), combined with the class bonus, ensures that my Fortitude and Will are pretty high to boot. Finally, since one at-will is usable as a melee basic makes Strength a pretty distant concern, and I think I'll focus more on Intelligence for a better Reflex and Arcana.
Since the store owner gave me a copy of both Chapter 1 and 2 for Keep on the Borderlands, I might use it for my own group for play reports.