Our Quinny got pretty rough and needed a new frame. We live on a cobbled road which probably did it. I wouldn't say they were very robust. I wouldn't buy one for the money even second hand (ours was free, and was very welcome, but I wouldn't buy one).
Lots of people get a Maclaren or similar small folding pushchair at 3-6 months, as they are way more practical if you don't actually go offroad all the time (most don't work for teeny babies).
We never used the big pram, as we live somewhere hilly, and it just didn't work for our baby. We used the ability to bung the car seat in, and then later on got a foldy up Maclaren.
Whatever you buy pram / travel system / pushchair wise, second hand is good - ebay is full of people who buy some beast of a travel system, use it for 3 months, then get a cheap folding pushchair and sell on the travel system dirt cheap.
Unless you live in some miracle place full of wide but extremely bumpy and rocky tracks with no stiles, don't bother with off road ability - that is what slings and baby carriers are for, and it just makes them bigger and more unwieldy. In practice hardly anyone goes offroad with a buggy (and once they're older, you can make most bike trailers into a running buggy for offroad anyway).