If I could take a wild guess that you are referring to the Whizlabs XML exam simulator, then I can only recommend it, it was vital for passing the exam.
If you're interested in general resources used to pass, then refer to my post from yesterday about the preparations I did for the exam. Other people have also posted their experiences and advice on resources as well.
I am not aware of any other paid product for the IBM Xml exam ...if you know any please do share it with the ranchers !
There are several free mock exams available for the IBM xml exam. You can find them at the XML Mock Exams List
The only disadvantage being that they dont have a lot of scenario based questions, which are part of the IBM exam
Considering the non-paid resources other than the free exams, you can start with the 3 articles that Pradeep and myself wrote for the XML exam and available at IBM developer works. Given below are the links for the articles
As mentioned by Bolton, if you are interested in other resources the best way to find that out would be by reading the posts of people who had passed the exam and have been kind enough to share their views in this forum
Hope this helps [ September 13, 2005: Message edited by: Hari Vignesh Padmanaban ]