I haven't switched yet, even though I've been talking about it for a few days. And just like Huff said-- It's not about being stumped by the challenge as much as wanting to pick the pace up. I'm playing Hard, 63% complete, Fall chapter, and played for 16h and 18min.
Right now, and unlike many others, I can't play play it for more than an hour or two at a time then taking an extended break. I feel like the game made its point about stealth, hand combat, and gunplay. I've experienced various enemy types and recognized their diversity. I'm done. I just want this game to be over with.