If I had a dollar (or better yet, a British pound!) for every time I've had to pry a manuscript out of a writer's mitts cause "I don't think it's ready, I'm not totally confident" I'd have enough dough to buy a round of drinks for everyone on this thread.
I'm glad you're seeing good results from one query. Now QUERY WIDELY.
Ha! I know well enough to listen when Janet Reid tells me to do something... and so I have queried widely. And gotten two more requests from SUPER mind blowing agents. I haven't slept in over a week...