I sent a manuscript to an agent a few months ago, and she finally got back to me this week. It's a no on the ms "as it stands". But she gave me a lot of feedback and said that should I revise, "don't hesitate to send it to me again". I agree with a lot of what she said (all of it, to a degree), and I wouldn't mind revising with her feedback in mind.
But she also said to send along anything else I have, and I just started querying a different manuscript. Based on her interviews, I wouldn't have picked her for either book (they're very much fantasy and she's been pretty quiet on that front), but I was referred to her by a different agent for an even earlier manuscript (an urban fantasy). So I can't tell if the new one is something on her wishlist or not.