I verified a substantial part of the statements on http://realdouayrheims.com/ .
Several translation examples show that the modus Lutherus (Christ systematically removed) indeed is used (as verified on drbo.org). Two quotes from 1909 Catholic Encyclopedia are correct. I didn't find anything inapplicable or unfounded.
Also, they correctly quote Cardinal Newman. He says that Challoner is "in the direction of the Protestant version", that Haydock uses Irish Dr. Troy version, commented by Newman: "we doubt whether he is further from the Protestant version than Dr. Challoner."
US$60 for a PDF (AT plus NT plus Douay Catechism of 1649) is not nothing. But probably I'll invest the dollars. Why? Beside the translation, original commentary.
It's good that you verified the statements from the article that Carissima posted.
To just further add a comment or two about that article - it says that of the twenty-one times that the name of Christ appears in the REAL Douay Old Testament, the name of Christ has been taken out of the Challoner and Haydock Old Testament thirteen times. The word "annointed" is substituted for the name of Christ. Five examples of this are provided about halfway down the article page.
The real English translation (from the 1500's if I recall correctly) of the Douay was never allowed into England after the Reformation, so Challoner and then Haydock undertook to make a translation for the English-speaking world, but it wasn't always correct. We English-speakers don't have a choice - we only have the Challoner or Haydock version.
I too might buy the version (supposedly from the original Douay) sold on that website. It may be a good investment.