I queried a novel about two years ago and got some agent interest. The consensus eventually became that my craft was not quite up to snuff. (In fact, one agent specifically told me to work on my writing style and recommended a book on self-editing.)
Long story short, I didn't get an offer of rep. That was fine; looking back, I agree with them that my writing was not up to par. Since then, I've found wondeful crit partners, studied the craft, and developed my voice.
I have now written another novel. It's very different from my first novel but also I think much better (though I may be biased :-) ). I went back into the query trenches. Unfortunately, my request rate is much lower than it was with my first novel.
Mostly I'm getting nothing but absolute radio silence and the occasional form rejection. I'll concede my current novel is strange and could be of niche interest. But how do I know if the high rejection rate is because it's a niche project or if my craft is still just not good enough? I've heard I should be getting comments like "I love this but don't know how to sell it" if it's a niche project, but I've never gotten any of those comments.
Let's remember one basic rule of querying: it's not the place to get any kind of feedback.
You got some interest on the first book; you've gotten none on this second book.
That is ALL you know.
The place to get feedback is from a very good writing workshop (Grub Street in Boston is one of them); a writers conference with critique sessions (CrimeBake offers those, as do many other conferences) or buying a paid critique from an agent. You can get those pretty easily nowadays in fundraising events.
As an example, Irene Goodman is offering this
Keep your eye peeled for others; the comments column will probably be of good use on this question.
Don't read any more into the lack of feedback than it was not a request. That's ALL it was.