What vehicle design will age the best?

[LK65EBO]

What current(ish) vehicle design would you say will age the best (London vehicles only) when the design reaches about 12 years old. Pick one Single Decker and one Double Decker (for best design ageing).   

My thoughts:
ADL E400MMC will age the best double deck wise. Single decker wise I'd say the MCV Volvo BZL SD.

For the worst ageing, double deck wise I'd say the BCI Tri Axel. Single decker wise I'd say the Irizar Ie Tram (358 vehicles)

Apologies if I've missed any vehicles out.

[BE37054 (quoll662)]

I'd say both MMC SD and DD (not the City)