I don't have date-check, but right now p411 has 162 provider listings in LA, 63 in OC, and another 20 or so in long beach, Pasadena, Ontario, etc.  It has definitely been worth it for me so far.

p411 is the best either works great!

And have had great luck with both sites. Date-Check has a one time fee for lifetime membership, while P411 has a $69 annual fee. They are both great tools for someone who does a lot of travelling.

It has been my experience that LA providers like referals from other LA girls, well know hobbiest that can verify that you are really a hobbiest or they want to call your work and see your business card.  Very few new LA girls that I have called for an appointment even know what P411 is.  I have never heard of the other service.

I am a P411 member and it is great if you are traveling to Tulsa or some other place without a strong network of providers.  P411 has just helped me only once with an appointment in LA and that was an agency.