If you take a long time to get your work to an agent (I’m talking 1 to 2 weeks) it says that:
a) You haven’t edited your work and you queried too soon
b) You haven’t finished your work and you’re finishing it now
c) You aren’t taking this process seriously and aren’t checking your query emails
Taking a long time to get us your work is detrimental because we may start to forget about why we’re excited about it; you are losing this great opportunity. One last proofread should only take a day or two at most if you want to do so. You’ve captured our attention in a big way and authors should capitalize on this focus.