Oxford and Cambridge questions

While I can't address the issue about transportation , a word of caution - Look at the term dates for both Universities . When exams are in session , many of the constituent. colleges are closed to visitors .

This is, I suspect, from one of his video's, as if it was in the guidebook, I would have thought the information would have been updated.

The bus concerned was the X5, run by Stagecoach.

Unfortunately the service has now been split so it is not a through service-
It is now Service 905 from Cambridge to Bedford Bus Station, then the X5 from Cambridge to Oxford with an overall journey time of just over 4 hours, including the change over at Bedford. Both journeys are ordinarily run by double deckers.
If you are here in June the £2 bus fare cap will still be in force so you will pay just £4- 2x £2.
This is the 905 timetable (it shows a change in St Neots- that is not accurate, because of the length of journey there are laws about driving hours, so a phantom change is shown- you just stay on the bus- it's a complicated subject, outside this forum's scope)-
https://tiscon-maps-stagecoachbus.s3.amazonaws.com/Timetables/East/BEDFORD/BE-905-080123.pdf
This is the X5 timetable-
https://tiscon-maps-stagecoachbus.s3.amazonaws.com/Timetables/East/BEDFORD/BE-X5-301022.pdf
If you knew it was run by Stagecoach you would use their website.
If you didn't know that you would use Traveline-
https://www.traveline.info/

The train journey via London would always be quicker, even with the tube journey, so this route is for the views, the cost (even on normal fares), and convenience as both cities train stations are slightly outside the city centre (although well linked on local transit).

The route replaces the former Varsity rail route which ran direct between the two cities, It is currently being rebuilt between Oxford and Bletchley (for Milton Keynes), never closed between Bletchley and Bedford, and there are aspirations to rebuild east of Bedford

1st April train strike, none further in April announced. So as long as your travel day is not the 1st:

That said, the X5 used to be a great service with excellent coach-like buses, leather seat, wifi, USB. The buses since the split into two are less reliable and often less fancy, sometimes using normal city buses. That's not from recent personal use but driving past the buses on the road - I use a lot of the route regularly.

That's not the way I would suggest to connect Oxford and Cambridge any more.

The train is very easy. There is at least one non-stop Great Northern train every hour between Cambridge and London Kings Cross station taking 47 minutes. There are other 1 and two stop trains, both Great Northern and Thameslink into both Kings Cross and St Pancras which take up to 15 minutes more. There are also slow trains into London Liverpool Street.

Various connections are possible through London to either Marylebone Station for Chiltern trains or Paddington Station for GWR trains to Oxford, both provide a fast reliable, comfortable service.

That's the way I'd go.

The X5 was made progressively slower by adding in more and more local stops, particularly at the Bedford to Cambridge end. At one time Oxford - Cambridge was under 3.5 hours. In the end it got too unwieldy.