Which one should I get as a client? Any comparison? Advantage, disadvantage? Prices?

I don't know what you mean which one you should get as a client?If you mean which one you should join for verification purposes just depends on what city you are in.Some of the sites are more favorable in certain cities.Go to each site and compare the advantages and disadvantages and whatever else you are looking for.

Room Service 2000 is primarily accepted in Illinois and the surrounding states and not accepted nationally.  Also, keep in mind that no matter which service you decide to use for verification, you will run into ladies who do not accept it.  They will, of course, accept the one you did not choose.

DC is only 125 for lifetime membership, p411 is 200+ for lifetime, don't know about rs2k.

Check and see which is most prominent in your area.  I have DC and p411, I'm in FL.

Swim

New England Area

Probably Date-Check and P411 are your best bet. RS2K is really only big in the Midwest. My vote is always for P411. It's easier to navigate and their customer support far surpasses that of Date-Check.

Happy Hunting!

Veronica Sweets