Cardiff IS nice.
Its a pretty small city, in a bit of a sleepy backwater in a forgotten corner of a declining nation, but it definitely punches above its weight for a city of its size.

International football, cricket and Rugby is a great plus - not many places can offer that and if we could establish ourselves in the premier league one day then that could also be a great boon to the city.
Shopping is decent
Bars and restaurants a bit meh.
Public transport patchy at best.

Programs like the Cardiff capital region should make a long term improvement, but its depressingly slow progress, it's just difficult to get hold of much infrastructure money if you aren't in London.