Apart from Decision Making, how much different will be my XAT preparation from CAT?

Hi
Let us first analyze a bit about XAT.
XAT will be conducted in January 1st week. The paper will be having 100 questions out of which 25 will be of general knowledge. The remaining 75 questions will be divided as follows :
26 Verbal Ability and Logical Reasoning
21 Decision Making
28 Quants and Data Interpretation
If you observe the sections apart from DM, all are quite similar to CAT.
For VARC the Verbal part will be slightly more in XAT as compared to CAT and there will be two poem RC's in XAT which do not come in CAT. The LR questions in CAT are more as compared to XAT but the level of questions is quite similar, the quants and DI syllabus for both the exams is same. So while preparing for CAT we cover many topics for XAT as well however we have to prepare for DM in XAT but in my opinion DM is one section which you can cover easily in one month.
But if you wish you can start preparing for DM now as well with one or two hours per week but currently focus more on CAT as your preparation for CAT will automatically compliment your preparation for XAT.