I think the General Mathematics course is generally harder than the old MIS course.
The past papers for MIS give some good questions for revision, but there are also quite a few areas which are new in the General Course.
Off the top of my head, you probably won't find any questions about these topics in MIS papers:
- Annuities & Loans
- Straight Line & Declining Balance Depreciation
- Box-and-whisker plots & stem-and-leaf plots
- Standard deviation
- Correlation
- Lines of best fit and median lines of regression
- z-scores
- capture-recapture technique
- error in measurement
- area of an ellipse
- permutations & combinations (not even done in 2 unit Maths)
- non-linear functions (parabolas, cubics, hyperbolas, exponentials)
But everything else should be OK!