Biggest issue with bone widow is the lack of innate magic armor. Raw hp and damage means nothing if you cant avoid some of the more dangerous forms of CC like terrify and charm. Bone widows also lack any ranged attacks and cant fit through a few doors. Sure it boasts massive HP, and a solid physical attack, but Incarnates are more versatile and make up for phys damage with +3 to spell casting skills for higher spell damage.
Not to toot my own horn, but check my Summoning and you guide. shows the whole tree broken down
