I eventually bought a new pair of road running shoes, my trail shoes being grumpy on the concrete ... It's the New Balance M1060WR (*). Designed for high mileage, lots of cushioning ... I just tried them in Hyde Park. They seem pretty good, altough I should have worn a pair of socks too ... Moreover they're made in UK, not in some dodgy Chinese sweatshop exploiting children.

New Balance M1060WR

Ultra ?

(*) This is a perfect example showing how Flash(tm) can be not only useless but also a real pain in the a** : I can't give you the direct link, you'll have to click yourself on "Cushioning", then once on the right arrow. That's more interactive, for sure ...