Hiya.
Your writing is good and your dedication and determination are good.
I was in critters for a couple months and when my reviews rolled in there was one that put me completely off of the site. This man was insulting about the most ridiculous things (character names, for example), he threw ad hominem at me (no idea why) and all of his insults of my writing were wrapped in language like "If you are serious about writing visit my website and read the pieces I've written. You can even buy my books there."
(I also find the critters website a bit overwhelming, but that probably eases with usage.)
And, the lag time between wanting a critique and being up in the queue as well as the week to get the critiques back, all of it was unwieldy. Like you, I did more critiques than I got back, and found the critiques I got back to be variable and not hugely helpful.
Having said all that, the short story that I submitted was not very good, in hindsight, but I was only a few months into learning fiction at that point.
That's my experience. I would have stuck with it had it not been for the self-promotional insulting jerk that critiqued my story. I was shook by his language and aggressive approach for almost a week.
I mean, there are random critiques here too, but because it is all public, the dynamic is more manageable, and you get to know people. We come to know whose reviews we personally find most helpful. Hope that makes sense. Like, there are so many different ways to write well, and just like we individually have different favorite authors we'd like to emulate, so too are there favorite writers we feel we can learn from.
A friend of mine enjoys critters dot org. Had that one guy not put me off so early in the process, I might have found my groove there.