I only used DONY once about a year and a half ago and it was all around fantastic. The girl (Adriana) was smoking hot (I wish she would come back around), and I had no problems with timing/scheduling. To answer the post above, yes, I received 2x. I'd imagine it's standard, but not sure.
The only reason I haven't visited a DONY girl again is because they only schedule M-F and I just haven't been able to make it work.