I'll chime in from a fairly unique position with anecdotal evidence only.
I feel like most of the advice you'll get is from experts that talk down to you condescendingly if you even mention the b-word.
I'll describe my scenario and you can interpret it however you wish. I have been wearing minimalist 'barefoot' type shoes casually since probably earlier than 2005 and as time went on I did more and more barefoot, though I am careful not to do damage to my feet (e.g. running barefoot shoed on pavement etc or on sharp rocks/tarmac where glass may be present, running barefooted on grass/sand/dirt only etc.). On top of this, I trained barefoot doing Kung-Fu for a few years. So, needless to say, barefootedness resulted in some strength being developed in my feet.
Because of this, my feet became extremely sensitive (in a good way) to the ground beneath them; I could balance my body using individual muscles in my feet. So when I first tried indoor rock climbing, sure, I tried their shoes, and hated them. Put on my barefoot shoes (0mm cushion 0mm drop, Merrell 'Vapor Glove' FYI) and I just felt better. I then did an outdoor climb on sharp limestone in Greece. Same thing: tried their pro shoes, took them off after one climb because I hated them. Put on my barefoots (this time they were by a brand called 'Cushie', VERY soft!), and loved the feel of them against the rock. Went indoor after that, same story.
My most incredible experience was literally last Saturday. I went climbing at Mt Piddington near Sydney. Again, I had hired a pair of pro shoes. One climb, hated them, had to take them off. Then I did the unspeakable: I actually climbed everything else barefooted. No, actually no shoes at all. You can check out photos of the barefooted climbing here. Why "incredible"? I felt so connected to the rock, I had the most intense exhilaration and adrenaline through my body. I had so much feel and control through my toes and feet. The two downsides is that there are some places you can't place your bare feet (e.g. wedged tight between cracks) and after a few climbs you'll experience a fair bit of pain. But I didn't get any cuts or bruising, and the pain subsided after a couple of days anyhow. Also it's true that 'edging' is a fair bit harder.
I'll confess that as a n00b, I was only able to complete one climb, rated at around an 8-9, whatever that means. I've been told that the only reason I was able to do it barefoot was because it was easy, and that harder climbs would be impossible barefooted. Well, I say: "challenge accepted", why not?
There was a wall that I couldn't conquer due to it's technicality. I attempted it first in the day, with the shoes. I'll just say that at the end of the day, with throbbing feet and fatigue setting in, I re-attempted the wall, and doubled my climb height barefooted. Take from that what you will, but it's enough evidence for me.
It wasn't until today that I realised what it was about the "pro" climbing shoes that I hated so much, but now it's clear: aside from the discomfort of having the foot squashed/arched in the shoe (which, by the way, I can sort of do naturally because I needed to do things like this in Kung-Fu), the shoes are just so rigid. My feet are used to being free and wearing flexible soles, not rigid soles (with a few exceptions like cycling shoes or going out shoes etc.). In essence, the rigidity in the climbing shoes didn't allow me to use the muscles in my feet or to feel the rock.
I am excited to continue training my feet to endure pure barefooted rock climbing whenever climbing outdoors. Though, to satisfy the requirements of gyms, I'll be purchasing a pair of Vibram Fivefingers because that's the closest thing I can get to being barefoot (socks only are counter-productive because soft fabric has less grip than human skin). I haven't decided which pair yet; I came here from a Google search trying to find the answer. You can't wear rock climbing shoes casually, but you can with the Fivefingers so it's a solid investment.
I'll finish by saying this: the pros all say wear shoes. On paper, the physics says wear shoes. Logic says wear shoes. But emotion defies logic. And even if it may be harder on my feet, I enjoy barefooted (with barefoot shoes or naked feet) climbing, and ultimately, I do the climbing for enjoyment, not to follow the textbook rules. Each to their own, your mileage may vary, I won't be held responsible, the usual disclaimers etc. I am a complete amateur: I've only climbed four times (twice indoors, twice outdoors), so I am no expert whatsoever. But this is my story, perhaps you may find the information you need from the scenarios I've described.
Take care, good luck, and happy climbing! :)