Just to add to this thread about response times from agents etc- 4 weeks is nothing, but it can feel like forever when you're the one expecting a response. Always a good idea to ask when submitting what the average time is, and then add on 2 weeks and gently remind/enquire. And do let us know, as always, about your experiences- we'll add them- as long as they're polite!- into our Directory. Good luck in the future.
I just tell myself that the longer they have it, the more they are reading and discussing it. Misguided optimism perhaps, but it stops me bolting for the door every time the post flap goes.