Your friends - your contract will have an 'exclusive' period, usually 16 weeks, though I've found they're always happy to change it to 12 at the beginning. They will enforce fees on any sale in that time. If you've been on the market longer, they can't, so check your contract.
I agree that EAs as a whole do bugger all for their money. I'm currently using Urban Sales and Lettings, which is one of a number of low cost online EAs who don't do viewings. I paid about £250 up front, they used a local surveyor for measurements, I wrote the blurb and uploaded pictures and I do all viewings. My ad is on Rightmove, crucially. They will handle negotiations. They are extremely efficient and helpful and I am impressed.
Why would I pay another £1,800 to a standard agent to do a few viewings? I can look up all the same info on local sale prices they can and know my house and neighbourhood better. I cannot see there is anything else they do for their money.
I really think EAs are going to change their business model massively over the next few years, they are, in my experience, poorly trained, complacent dinosaurs - as an industry - albeit some rare individuals are really pleasant and helpful.
You're being a bit unreasonable about feedback though. People do look at lots of houses, form an immediate yes / no / maybe impression and say vague things. Only the close 'maybes' might have anything interesting to say. That's the same whoever is doing the viewings.