I have not had to encounter the ESA medicals personally, my claim started before the commencement of this, but have read many of the posts on this forum relating to the nightmare experiences people have had with this particular humiliation. I do not know if this will be of any use to people who have to deal with the ESA medicals, but I have found the official handbook (in PDF format) used by the ATOS doctors. The book can be downloaded from:http://www.cpag.org.uk/esa/mstd_esa_hbk.pdf
At the very least, reading the book will give you detailed knowledge of the medical so you are better prepared for it. Hope it helps.