Normal for me..
just to get to grips with the game.
First play through either easy or normal with no hardcoe. One subsequent play throughs I'll try hard. To be honest though, hardcoe does not sound fun at all. The fact that I now need to drink/eat/rest seems like it would be more annoying the fun. Also, it would svck if your out in the wilderness and you step on one of those invisible mines and now your crippled. So, unless you are lucky enough to have a doctors bag you have to limp your way back to civilization just to get healed.
"Oh no. I'm dehydrating. Let me quit exploring and killing monsters so I can look for some water."
I know I will end up being an hour into exploring and I'll start getting dizzy or whatever happens. I see little to no fun in that.
I get that it adds a new dimension to the game but, it seems like it will be way more annoying and frustrating then fun. I predict that the people that use it all the way through will only use it for the achievement. When half of your deaths are from starving you WILL NOT be having fun.
Just my $.02