As for the SF novel - so far I have received no responses at all. Not even form rejections.
Which is no more than I'd expect after one week. I've heard of agents responding (yay or nay) within days, but most of them say to allow 6-8 weeks for a response, sometimes longer. And unfortunately, nowadays an increasing number of agents don't even send form rejection letters - "No response means no" as a default policy is becoming common.
This does make the idea of only querying a few at a time to see how effective your query letter is problematic, since it could be months before you get enough feedback to have any idea if it's your query letter that's failing. So I am querying a little more widely, though once I exhaust my current list, I will wait a while before I start gathering more names. Also, most agents' submissions guidelines instruct you to send the first few pages, sometimes the first few chapters, along with a query letter. So the general lack of feedback also means even if I do get a no, I won't have any way of knowing whether they never even got past the query letter, or if they did actually read the writing sample and hit the reject button at that point.
Please note, I'm not griping here, just spelling out the way things work. You can see writers complaining, ranting, wailing, and overthinking things on any writers' forum. But it does no good to whine about the way the industry works. If you can't stand it, self-publishing awaits.
I admit, though, I'll be glad to receive my first form rejection, just so I know that yes, someone did actually spend a few seconds reading what I sent. And it will be my first real, official rejection — a true badge of being a writer!
Would be much nicer to receive an offer, though. :)