I have lived in both, and did love both. You are right about the similarities! Oxford has some of my favourite pubs and restaurants, I would prefer to eat out in Oxford rather than Cambridge. Cambridge seems to get more clogged up with tourists, but maybe that's an erroneous impression.
Oxford is quite a bit bigger, less green, a bit less flat! Maybe that would be relevant for cycling. Lots of people do cycle in Oxford of course, but it seemed to me a bit less safe for it than Cambridge. Trying to think of facilities that Oxford has that Cambridge doesn't - can only think of the ice rink, and maybe the Covered Market (which is great).
Cambridge centre is much more attractive imo, with regards to shops and green spaces - it's a bit more spread out and leafy. Particularly since Cambridge renovated Lion Yard and the bus station, which has made it much nicer round that area. Oxford seems to have more truly grim bits - Oxpens Rd, Botley, Blackbird Leys -, probably just because it is bigger, and of course there are lovely bits too, and it does have green spaces like the University Parks, Christchurch Meadow, the Oxford Canal, the Thames...
Oxford arguably has better transport links. In particular a fantastic coach service to London, and to the airports that runs through the night. The railway station is less of a trek. But the traffic problems are dire, and it's awful in a car.
Cambridge seemed to get a lot less rain than Oxford
, but to be a bit colder.
I don't know about friendly villages round about Oxford, I lived in Oxford itself. Most of my colleagues lived in Abingdon, which is nice enough, and has a very good bus service to Oxford (but no station).
If I was you, I probably wouldn't want to move either, and now, no longer living in either, if I had to choose one to return to, I'd probably pick Cambridge (only just though!) and I think DH would choose Oxford. I don't have experience of living in either with children - mine are quite young, which I think would partly influence me thinking Cambridge is better. If I had teens, maybe Oxford.