After 2 years I am a quite happy Curve D3 owner but I think I'm getting flat tires too often (and replacing the rear tube is so annoying...). I'm still using the original Big Apple tires and the rear one is already a bit wored so I'm thinking on replacing them with Schwalbe Marathon Plus. I know those tires would not be as comfortable as the Big Apples but I wondered if anyone did this before and how it went. Other comments regarding Marathon Plus will be appreciated as well. Thanks in advance!