Right, finally got these fitted. Got one side done on Monday, then it rained for the rest of the week, but luckily we had a free window of dryness this morning (raining again now).
They still time to bed in as they've done less than 10 miles, but they are sooooo much more powerful. (Will do measurements when the ground is dry again.) But they feel like they should be a lot better. There's still a little bit of dead pedal travel at the top as there was before, and the brakes are still quite heavy, but the feel seems much better.
Slamming then on at 30 is near instant standstill, and really throws you forwards in the car. I have noticed the car starts pulling under braking more - it always used too but it's more pronounced now. I intend to lower it and renew all bushes soon, so hopefully that'll fix that trait!
Before I found that if you were braking from 60-70, but then needed to brake harder (car in front stops more, or a misjudgement) then there was no real feel as to what was happening and it could be quite scary. That seems gone now, if you do this then there's much more feel and the car stops pretty much instantly which is always good.
I'll update this with more thoughts/distances once they've had a while to bed in, but I think they're going to be much better.
If anyone's local they're welcome to a quick try.
Also remembered how much better the Polo is than the Golf! The Golf is
the worst car I've ever owned and I really wish I'd never bought it. Love the Polo though!
Update
Just been out again to the same place as before via some back roads. Just as I got there, it started to rain. Typical! I did a couple of runs and they seemed to take longer, but I'm hoping it's cos the surface was quite greasy (was getting some understeer too which I don't normally). They are massively more powerful though - the ABS kicks in near instantly, and if you look it's leaving rubber marks on the road you second you hit the brakes from 60, in the damp.

I counted about 32m 60-0, which is ~6 meters longer, but considering the conditions I think it's a good result!