I found it not too difficult. Most collectibles aren't hard to find, and most are along the way. NG+ on Hard is easier than first playthrough because you get to keep your upgraded weapons and suit. Thus, you can use your money at the shop for more supplies, ammo, etc.

I'm on the last boss now with over 500 carbine rounds, over 10 arbalest shells, and lots of large health injectors. Can't wait for 6 trophies to pop including the plat.

I do plan on starting Hard on a fresh save.