My kids are 17&18 and at that age,
to keep myself sane and to give them responsibility,
and everyone can enjoy their holiday,
i book them their own standard room and take a connecting standard room adjoining
(or a suite + connecting room adjoining)

i once tried a duplex:
as others say:
- noise from the lower level travels upward
- 2 bathrooms is handy though
personal:
- when traveling and everyone's bodyclock is messed up: lots of grumpyness with lights turned on/off
- i am not good with stairs