With an IS20 id say it will be perfect. Not too much power that its silly and overpowers the tyres all the time, but also the turbo wont come on as instantly and as early as the tiny IS12 so it will be better to drive id say.

When I got my little Fiesta ST I was also considering the Polo GTI (about 2015-2016 model with 1.8TSI) but there were none anywhere near me for sale with a manual gearbox. Id like to compare the two in terms of engine/gearbox and how they drive.