PB because it's faster, indestructible, and has low strength requirements. The speed is the most important thing. The damage difference is not going to be noticeable either. The -% enemy res will not be as good as the + skills from HOTO though, especially since the skills will help all your trees, including, say, curses like Lower Resist.
So you're saying to go with the HOTO instead of Grief?
What if I told you that I had the full Trang's set, Marrows, and a +2 skills amulet. Would you still say that I needed the HOTO for the + skills?
I'd definately pick the HOTO. It offers a great number of mods, and with three peices of the Trang set you're already getting -25% enemy poison resist, along with some socketable gear. Plus you can Lower Resist them, which will help. The grief wouldn't help a great deal, really.
HoTO also has some nice defensive mods (resists anyone?) and fast cast, which is wonderful.
I wouldnt go out of your way for fast cast in PvM, it never hurts in PvP.
my poison necro has a low 2/1/41 deaths web but I did use hoto for my lower levels and I was pretty fond of it. I got 10k novas with a 50% bramble that I made, and retired my poison necro after that. good luck...