Never been myself but this has been on my radar for ages. A mate of mine who does urban exploration mentioned that mill about a year back, said the lower levels have this really oppressive feeling, like the air gets heavier the further down you go. He's not someone who spooks easily either.
I've had similar sensations in old industrial sites here in Yorkshire - there's something about places where people worked brutal long hours, often in dangerous conditions, that just seems to leave a mark somehow. Whether you think thats residual energy or just your own brain picking up on the history, it's hard to shake.
Anyone managed to get decent photos down there? That kind of enclosed stone or brick space can throw up some really interesting results. I'd love to see what people have captured. And has anyone actually looked into the history of the site, any incidents or deaths recorded there? That context always helps when you're trying to work out what you're actually dealing with.