if you can go to London without financial issue,bartlett and aa will be first choices with westminster and london metro be insurances.
cardiff is too traditional,not for experimential or radical dreamers.and school focuses on technology much more than individual/conceptual development/design.
so,it is very different from AA or bartlett.
the difference is because of opposite attitudes and opinions on economic/utilitarian determinism.
as you said u are international student,therefore I do not suggest u come here as I know most of the oversea students not satisefied here because the school is just smae as mid-upper schools in their home country.which means they did not really get lots of advantanges than their friends in home country.
the ranking by AJ education survey,cardiff and sheffield are the samples of top relative traditional schools,and you can see Bartlett and AA,oxford brookes,wesminster are top experimential/conceptual schools.
conclusion:if you want to be a high qualified student,most of UK schools are your choices,if you wan to do something different and more advanced than your home country students,AA,bartlett,Oxford brookes and westminster and other london schools are your choices as they have got different education system for decades already:the UNIT system.The traiditional schools like cardiff,shef,liv do not have UNIT systems but I think they will make changes soon because they recently noticed the global competitive enviroment.