Ancient White is brutal.
The ships all suck if anyone knows that's your black, but with the new system this is mitigated.
I always thought the Siege Encampment was bad, but if you're smart, you can bypass a lot of the terrible shit. The fucking battle to get that black is brutal though.
Veran can be bad at times, but in general, I'd label it with Pine Forest and Teth in terms of difficulty (can be gathered without using up multiple barrier charges).
I more had a problem with absurdly easy spots (spots you could get without even using aura). Pine Forest COULD be that way, but unless you were Conjurer/Air Shifter it was still a PitA. Festpath and the Demon of the Sands were super easy. And if you were a goodie then the Mortorn Black was CAKE. Brass Dragon could be real easy depending (could see him being slightly a bitch for a transmuter).