I've calculated the corresponding effective interest rate for comparison.

Citibank  flat rate -  effective rate
2 years - 7.60%  -    13.97%
3 years - 7.68%  -    14.00%
4 years - 8.40%  -    15.00%
5 years - 9.18%  -    16.00%

OCBC Power Credit
1.4% per month = 18.16% effective per annum

Normal Credit Card
1.5% per month = 19.56% effective per annum

This does not take into account all the other charges (eg processing fees etc)

Hope it helps.

Besides looking at the interest rate, please beware of the hidden charge and some term & condition, like processing fee, guarantor, collecteral, some just for gov servent or for bumi only.