Hello Eli!
To start, thank you for your help in advance.
We need a stroller that will go through cobblestones, holes in the pavements, but also off-road - forest roads, gravel... I also need it to be modern, streamlined - something with a good-looking design, but not too robust. I will need to fit it in narrow elevators... Ideally, it should feature a reversible seat unit. The budget is not really limited, but it would be nice for it to be less than 600/700.
Thanks again
Hello!
With these requirements - something really capable even in harsh conditions, but not too robust, to fit narrow elevators - I will recommend only one thing, realistically. Check the Emmaljunga NXT60 (bucket-type, ergonomic seat) or the strollerbase NXT60 F (F = lay Flat, non-bucket seat) models. They're small enough while being incredibly sturdy, and mainly with the Outdoor wheels, they'll pass through anything. They are also rather expensive, but so well made they'll be able to be used even with multiple children. That is why I will suggest looking for pre-owned ones as well, not only for financial but also for ecological reasons 😉