Swift 1.3 engines are pre historic technology... They were replaced way back with the 1.2 more fuel efficient and almost equally powerful engines...
Vitz 1.3 is more fuel efficient... I havent seen a manual 1.3 yet but seen a few 1.5 RS. Those things are like a dart. Light body and powerful engine makes for a very agile car...
So in the end its just a matter of personal preference....
P.S: This topic has been discussed before...
Cheers...