Over the years I've owned a Mk5 Zetec-S, a Mk6 ST and been in (and also driven) the Mk7 ST and latest Mk8 ST. I've also recently owned the latest Polo GTi. And I can honestly say I wish I'd never bothered with the Polo. I have no experience with the lower trim levels or engines in either range, but the Fiesta just has something about it - certainly more engaging to drive and I've always liked the gearbox (manual) in the Fiesta. The Polo I found mind numbingly dull and dreary to drive with soulless steering feedback and I hated the DSG box (all it ever did was change up as quick as it possibly could, try it in Sport and it would want to rev all the way before changing up. No happy medium). Brakes were far too aggressive on initial application, no matter how gentle you were. Interior I wasn't impressed with either and I found it was mostly cheap scratchy plastics. The moo'ing from the rear brakes when reversing and sticking handbrake were also very annoying. Then you have the possible longevity issue with the EA888 engine and carbon build up. Although I sold the car just after 12 months of ownership so not really something I can comment on either. I'd go for a Fiesta if I had to choose one.