I'm not an agency guy so can't really comment, but are Lush the agency du jour at the moment? Nearly every other post seems to be about Lush or one of the girls they have!
Thing is MrSD that for an agency they are really cheap @ £120ph and that's fascinating for some of us tight Yorkshire folk. Other thing they have is Indian/Pakistani lasses. Umm I like podging an Indian/Pakistani lass but TBH after reading the reports that there currently are I ain't tempted.
Then there's this issue of service with a menu. Can a chap pop more than once in a 1/2 hour booking etc.
I go by the mantra you get what you pay for !!! My money will therefore be spent at IK or Playmates as I would rather spend the extra £30 and be reassured by the knowledge I will get a good service without strings/menus attached to it.