I've used them a few times, sadly.
The polish woman who runs it offers little help, simply saying, "All of our girls are beautiful". She won't give you any help when picking a girl only by saying they're all stunning - they most certainly are not.
The receptionist who I think only does Saturday/Sunday is more helpful.
I'm almost certain the Polish owner writes her own on-site reviews too, so be sure to take no notice of them. Most of them have spelling/grammar errors, as if someone from.. erm.. Poland had written them.
My overall feelings are similar to the other agencies in the West/South Yorkshire - shite, with a few good girls working, but the majority making you feel like you've just wasted your money.
Do your research. Layla is the ONLY girl I would see from AngelsNorth again.