It's odd how these subs differ from erotica subs for me. These days, I know I have at least a 50/50 chance of publishing an erotica story; I know roughly what level the market's at, and I know that my stories are good enough, so it's just a matter of editorial tastes. I can be sort of pleasantly smug as I'm sending off those stories.
It's different for sf and literary fiction. In theory, I think my writing is generally good enough for the sf markets. But that's my writing overall -- in specific, few of the sf stories I've written feel really properly finished to me ("Amanda" may be the sole exception, and there are other problems with trying to sell that story). I'm not sure why I have such trouble writing in that genre. So I have this sort of sneaky feeling as I'm sending those off -- a kind of "I'm pretty sure this isn't good enough, but maybe you'll take it anyway?" thing. Not comforting.
And for literary, I'm just not sure I'm good enough at all. I'm pretty sure I'm not good enough for the top markets, but I'm starting there anyway, and working my way slowly down; it's good policy in theory, but in practice, it's discouraging -- and slow, since they take so long to respond. In September, The Kenyon Review opens to subs again; I'm holding out slightly high hopes for them, since their editor expressed an interest in my work. We'll see. Eventually, I'll work my way down to my level. :-)