In reply to The Potato:
Have never used a Weeride, but did use a Hamax and a trailer (and a tag-along later on), and looked into the Weeride at the time.
Pros and cons I can think of
Weeride
Pros - you can see your child, hear them and easily tell if they are happy, it's sociable
Cons - like others have said, some people can't pedal with one installed, if your child is big, you'll struggle to see over them, if they fall asleep leaning out of it you have a problem, the child takes full brunt of weather, flies, wind, grit etc
Trailer
Pros - More weather protection, you can carry some luggage as well, or another child
Cons - you can't see or hear your child all that well (esp if it's closed up when raining), it's a right pain if you have two kids in there and they start fighting. It's wider and takes up more space.
Not sure I'd be too worried about where you can go. My other half happily towed our two oldest children up to both White Bridge and Derry Lodge in the Cairngorms (tracks but fairly stoney in places) in our second hand Burley D'Lite trailer. Kids both fell asleep, which was pretty much standard when out on the bike. They'd perk up at the destination and we'd both be knackered!