Once the solicitor's start talking then the main use for the estate agent is just keeping you updated on the other bits of the chain. You can't (legally, or just generally in my experience) rely on what the estate agent's are saying so ultimately everything needs to go through the solicitor.
My solicitor didn't speak to the estate agents at all and that didn't cause any issues for me. (The estate agents bitched and moaned about it but without any good reason).
tl:dr Pick a good solicitor, someone who is easy to get hold of and can answer your questions and progresses things quickly. That probably isn't the one recommended by your estate agent.