User blog comment:Xilinoc/Ch. 642 - BABY, HOLD YOUR HAND 5 (EYES ARE OPEN)/@comment-24099400-20150910140940/@comment-26091912-20150911024731

Not necessarily. Although she's overwhelmingly strong in this state, it seems to be a last resort only, as it burns up her life-force rapidly.

When Kenpachi lunged at Pernida directly, he was able to cut partway through it with his left hand (he's right-handed)—Nemu destroyed an unsuspecting clone, so it's not really a valid comparison. It doesn't make her "captain-class" anymore than Uryu just because he can use Letzt Stil.