Totally agree with DS3
I don't think anyone would say that a credit report is ever a reliable way of assessing that there is no risk. But they're sometimes a very good indication that there is high risk.
This, along with some of the more sensitive research you can do - such as the one suggested by IO540 - should be used whenever paying in advance, should you personally decide that you are borderline on the risk you're taking.
Each case has to be taken on its own merit. Blanket "don't pay in advance" statements are just as worthless as blanket "pay in advance" statements - it all depends on the individual circumstance.