I lived in Cambridge itself for a while, not too far from the main Cambridge station.
I quite liked Cambridge itself, although once you live there you do start to discover that there's a kind of invisible separation between the university and the town. There's a lot of interesting cultural stuff that goes on, for example, that is only open to university students and staff.
But the commute to London drove us both mad after about six months. And we were very close to the station (at the Cambridge end).
You will find that whoever is doing the most commuting in your case your DH by the sounds of it will have an utterly miserable time and will likely ultimately regret the decision to move.
What I tended to find is that there was a massive scramble to get seats on the King's Cross trains in the mornings. Literally pushing and shoving. The train then filled up even more at Royston, with people standing in the aisles and around the doors. It was no better than London commuter trains really, and very uncomfortable.
Likewise on the way home -- as soon as the Cambridge train was announced there would be this crazy rush to get on it and get a seat.
A delay to the trains would knock out a whole evening. Even when things were running well I would seldom get home before 8pm. (I would finish work at 5.30, but then have to get to KGX which could take up to 45 minutes, and if I missed the one convenient train I'd be waiting 30 minutes for the next one.)
I started getting the Liverpool Street trains, even though that meant a 20-minute longer journey and an inconvenient half-hour bus ride at the London end, because the trains were newer and more comfortable, and the rush to get on them at Cambridge was less intense.
I really, really wouldn't recommend it. I thought I'd be fine with the commute ooh I'll get loads of reading done, I thought but the reality was cramped, uncomfortable and hot trains, jam-packed with other miserable commuters like me, feeling slightly sick all the way because the trains rattle along quite fast between Royston and London but they rock side to side quite a lot on the rails. As I say the Liverpool Street trains were slightly better but were more subject to delays and cancellations for some reason.
Bear in mind they also discourage car parking at both Cambridge train stations now. In fact I'm not sure there's much of a car park at Cambridge -- what used to be the car park when I lived there is now the (very nice) Tamburlaine Hotel.
Plus it was so expensive -- the train season ticket was over £5,000 a year and that was five years ago.