I just got this neck on a raid and as a Solo heavy Beastlord I find ac>hps, with self buffs I can max my sta easy and have descent hps but when I solo if i have 3khps or 5khps it makes no difference if I get damaged more means more downtime is all so ac helps much more than hps. At my current level 62 where I solo I melee mob about 75%-100% after pull, using chloro as I melee when i get under 75%, at 100% mana/hps I usually use bout 20% of each and with c3 and my fungi staff can replinish it in bout 1-2min and go pull again. BUT as for raids YES hps>ac for sure.
Maybe BST is the only class that solo's much post 60 I am not sure as its my only post 60 char but AC very important to the Solo'n Beastlord.
Gatorr lvl 62 Troll Savage Lord