All I know is that they advertise in Writer's Forum and charge a fee for reviewing a manuscript. If they consider it likely to interest mainstream publishers they award it a medal of merit and 'exhibit' it to literary agents. Probably all the above is on their website and you know this already. There are a few companies and literary agencies who offer this service, (Abbey's another that looked interesting) but I've never used one so can't really help much. I should check out a number of them if you're thinking of going this way.