Hi, Does anyone have any experience of either of these off road - not major stuff, just gravel path and a river bank (uneven grass / mud surface etc). I'm considering both for ourLONG winter doggy walks for my 3.4 year old and 4 month old.....Any advice would be great- going round in circles here!! (I've also seen the Kolcraft Contours Optima which looks much lighter and slightly smaller- again, anyone with any experience of that one? Thank you lots and lots :)