Emilian,
I too studied at CATS and also had the Oxford material. I found that CATS was sufficient and covered all the necessary points. The Oxford material was also sufficient, and the material was written in another style, which helped with understanding sometimes.
I don't know if the 2001 material is that far off, but the only changes that may be relevant are within the law section. Although, other subjects may have been updated to more accurately reflect the current testing areas.
Why don't you just stick with the CATS material for now, and then supplement with Oxford where necessary.