Only difference I can tell between them by the specs is the weight, the 3 wheeler being .5 heavier. I was dead set on getting the 4 wheel after testing it out in store but it hasn't been in stock for a while and I've only got 5 weeks left of my pregnancy until my due date hits so I need to decide soon if I just go ahead and buy the 3 wheeler instead. Is there much difference? Is the 3 wheeler just as stable and secure as the 4 wheeler? Is it harder to fold? Does it just depends on the terrain? I'm probably going to use it on pavements a lot. I now wish they had the 3 wheeler next to the 4 wheeler when I was in the store so I could test out both but they didn't. Anyone who's had the Mothercare journey or has had lots of 3 and 4 wheel pushchairs who can tell me the difference would be helpful! x