Critiques not only help with flow, grammar, etc, they show different tastes and enjoyments. Opinions do matter.
I had the pleasure of hearing an agent's critique of one of my queries. What was so cool about this crit is it confirm all my betas' opinions as well.
Diamond Black is a wip that is waiting in the wings until I finish several other projects—my third book in The Magic Withheld series, for instance. I'll polish up Diamond then.