Histon is fine if you drive/own a car, otherwise it's too far out. That said the buses are ok and as a non driver I do regularly visit friends without too much difficulty.
In terms of looking ahead to secondary school then a main reason to move would be to be in catchment for Impington Village College. If you are off Mill Rd then your catchment schools are Parkside or Coleridge. The latter sometimes divides opinion. About 1/3 of our Romsey Town primary school went for Netherhall in order to avoid Coleridge.
Regarding primaries in Histon. It may still be the case that they have an infant and junior school set up rather then a straight primary. If so, they have different uniforms, which is really silly. Also, the infants were so over subscribed in recent years that some infants classes actually were actually in the junior school. But, I think the schools were well regarded.
In Histon the houses are larger but mostly less characterful than those off Mill Rd. I'm an urban kinda creature, so it wouldn't suit me and part of my qualm would be that it's not too different from Cherry Hinton in the sense that it's a long bus ride away, is a big village and has a fair amount of modern housing. From my perspective that's the suburbs supplanted to the countryside.
But ... if you don't feel like that it has The Geographer, a football ground, some shops etc, good schools, affordable houses, churches and so on.
For me Mill Rd has it all and I can live with the minor downsides of that. The house prices have gone down a bit but they are never very low - not since the 90s anyhow.