I must not have ridden the same Brompton: Mine was bouncy, with stupid handlebars, wouldn't climb well. In contrast, the frame of the Helios P8 is a dream and good eneough to climb in the Peak District, albeit slowly. Bar ends are a good idea as are Marathon tyres (stock on the Dahon) indeed. The only thing I changed was the saddle: Too soft for the original, so I got a racing saddle on and it is great. All within £500 as well, including guards and a usable rack.