I currently live in Cambridge. Before that, I lived in Oxford, and before *that*, I also lived in Cambridge. I've worked for neither university (though my partner worked for both of them, which is why we moved) - I work in the high tech sector. The journey between the two cities is not much fun by any mode of transport: it's a 2 hour journey by road (sometimes a bit quicker if the motorways are quiet). I did it regularly by train for a while, usually on Friday and Sunday evenings. It takes a smidge under 3 hours as planned by the journey planner - sometimes if you're lucky with the tube connection you can do it in two-and-a-half. The frustating thing is that the direct journey is only 85 miles: a decent rail service could do it in a bit over an hour. The journey via London is frustrating - the trains are usually busy and the journey is in three sections so it's not like 2 hours on an intercity train where you can get some work done - you're sat down for 40-50 mins on the Cambridge leg; have a 20 minute tube ride and 30 minutes of waiting around at Paddington; then sat down again (hopefully) on the Oxford train.
Don't even start me on the X5: you can't really work on it without getting seasick. It is better than it used to be because both the roads and the coaches have got better, but I wouldn't take it again unless price was the most important factor.
Had EWR been running, we probably wouldn't have moved to Oxford when my partner got the job offer - it would have been reasonable to commute. Even now, we rarely go to Oxford to visit friends because the journey's unpleasant. A direct rail service makes it an attractive day trip (for either work or pleasure), and it also makes Milton Keynes even more attractive as a place where you can commute to Oxford, Cambridge, London or Birmingham all in less than an hour.
But the big benefit is all the other connections. In one of the various EWR studies I was quite surprised that Cambridge-Northampton was considered an important route in terms of passenger demand. That's an extremely tedious journey right now by rail, and one that would be very quickly improved with a connection at Bletchley. Likewise it would be great to have better connections to cities served by the WCML and MML, rather than going into London and out again. Giving the East Anglian towns and cities a better connection to the west will help too - at the moment you've got a choice of a long detour via London or a scenic tour of Cambridgeshire before you can get to the rest of England.
