"Mine won't be a popular opinion. Sure we'd like people to be prompt.  Sure we eager--even anxious.  But agents are bombarded. It's OK to ask for a confirmation after a few weeks.  It's even OK, if you hear back from one with some tips and a rejection, to send them something back saying you utilized some of their tips and asking for a re-read. And when you do, polish a little. Let them know why you want THAT PERSON for an agent.  Hey, guys. Agents are human, too. 

 

Having said that, if you find one perennially tardy, and that bugs you to death...well, maybe that one isn't the right one for you!  And it is fair to say (if you get an offer), "Hey, I'm a prompt person and I'm wondering here if you are always so blamed tardy, you know??"  It could save you lots of headaches in the future and the agent may very well tell you it is the acceptance process that is slow...that, once accepted, they move quickly.  Of course, then you'll have the publishers to deal with and so will they.  I think you get the picture, here, right.