So far(and I am early into the game) the difficulty of Hard mode, much like classic RE, merely extends to crucial item distribution. When I have a decent supply of ammo, the game is a cakewalk. When random drops suddenly spew forth a steady stream of money and healthpacks to the point my inventory is bursting at the seams with needless band-aids and my weapon has less than a full clip to its name...that's when I start dying.
My last save is at a crucial action section where I am assaulted by a small swarm of enemies. My magic meter is empty, my gun has just enough ammo to kill a single guy, and my only option is to just run(meh), or hope that I get lucky enough to get ammo drops from each corpse I barely pick off while I stave off the rest of the invasion with a super tame melee attack. But I do have gobs of health rejuvination to keep me in the fray.
So it's just very artificial.
Also, this game is about as scary as RE4(so not at all). Coming off of SH:H, it's a generational leap in visual fidelity and presentation, but the combat and audio is so active that environmental "whats dat!??" and ambient aural growls and clanging don't facilitate dread the way I expect is hoped. Also, necromorphs are very videogam-ey compared to the hideously disturbing creations you face in SH:H.
It's still a fun and gorgeous game to get lost in, and the dismemberment turns the tired 'headshot' design somewhat on its ear. RE4 fans will find it a fantastic way to fill the void left between RE4 and 5.