I don't see why anyone would want to step down from a GTD/GTI to a polo other than as a financial consideration.
It depends on how you look at it.
The Golf is big and heavy and has a lovely high quality feel about it.
BUT the Polo is fun.
Yep, the Polo interior isn't a patch on the Golf, the electronics are a generation or half a generation at least behind, you get nasty painted metal bits on a five door by the rear window, the wheelbase is shorter and it's a taller car so it's not as stable... I could go on for hours pointing out the negatives.
However - the Golfs, despite all the electronic aids can be as dull as ditchwater to punt around at legal speeds.
How many on here have said their mk7 isn't as much fun or doesn't feel as quick as the figures suggest?
Just look at the used values of Lupo GTI's now compared to Golf GTI's of a similar age. Is the Lupo GTI fast? No, it ain't but it's FUN.
The Polo GTI is no Lupo GTI but motoring is getting so watered down now, and Golfs are so refined as standard cars they've lost that little spark that used to distinguish that sporty models - and I'm going right back to the early 90's here when the Golf decided to be all things to all people.
Is a Polo GTI a better car than a Golf GTI? Not a chance but it could well be a lot more fun to drive and sometimes that, added to the financial considerations, makes it something worthwhile to own.
In an ideal world it would be nice to have something fun like a Polo GTI or Mini Cooper S for days when you're in the mood and a Golf R (or GTI/D) for other duties and I think that's what a fair few on here will consider.
I'd consider a Polo GTI over a Golf GTI as I don't need a biggish car 99.9% of the time, but at the end of the day it's always nice to get back into a Golf GTI as it has just that little something that other cars don't have, the ingredient X.