Saw the new Swift at the motor show and the cabin space is crampy. Interior layout is very basic although it scores on the exterior.
Vios is also a good choice but there are just so many on the road and it will affect the resale value. This has happened to the Sunny, whereby a lot was sold at near or scarp value as they simply have no value in the 2nd hand market. Singaporean are kiasu and most will follow the herd and play safe.
All said go try both Vios and City and make your choice.
A comparison, based on my opinion and test drives review from magazines:
Exterior(score of 10)
Vios: 7 (conservative styling, well proportioned)
City: 6.5 (futuristic styling but polarised opinion, especially rear end)
Interior
Vios: 6
City: 8
Boot
Vios: 6.5
City: 8
Engine:
Vios: 7.5
City: 7.5(iDSI) vtec 8
Saftey:
Vios: 7
City: 7 (vtec)
Handling:
Vios: 7
City: 7.5
Quality:
Vios: 7(recall recently)
City:7.5(no recall scores higher)
Modification

exterior, engine)
Vios: 7
City:8
Cheers!