For NUS/NTU application, there is not much
difference, however, a strong students may want to take up H2
Maths/Physics/Chemistry/Biology just because he/she is not yet
certain what to do in university. (medicine requires H2 biology and
engineering requires H2 physics)
However, if a student intend to apply for top universities in
U.S, with a scholarship offered from local organisation, then 4H2
is much better than 3H1+1H2 which is just the standard.
Correction: H2 biology is NOT needed for medicine.
H2 chemistry is.