Are the Agency girls mostly bait and switch that are posted on Cityvibe, Eros, and LaExotics.....

I don't think they're all bait & switch. I think your best bet is to look for realistic photos, and check reviews. The only agency that I've seen with consistent reviews and real photos is BDJ.

                            OR

You could go independent

My one experience with a fairly expensive agency provided me a very good girl, but it clearly was not the girl in the picture.
They tried later on to convince me it was really her. . .