I'm somewhat of an old timer I'm afraid, but I also think having been left a year (doing an MSc at Newcastle, in-fact), I'd like to think I can give a fairly objective overview of what a week in Cambridge used to be like.
Subject: Geography, College: Selwyn
In geography, like most arts subjects, you seem to get 8-12 supervisions a term (pretty constant over the 3 years for me at least). The workload picked up in 2nd/3rd year as there was coursework and dissertation to consider as well. I found myself spending 4/4.5 days a week on 1 supervision essay for sure. Then either: 2.5 days coursework/diss, 2.5-3 days for the other supervision or on blissful weeks, had a weekend (or mid-week) off. This framework was pretty set, and seems pretty standard for many 'Arts' subjects.
Typical Week:
Monday - 10am - 2hrs lectures. Lunch. 1pm-ish Go to library, start main weekly essay reading. 6pm - College, Hall, waste about 2 hours after dinner. 9pm-1am, reading, bed.
Tuesday - Day off lectures. All day library, hardcore reading for said essay. 4pm Insert one of my society/committee meetings here (I didn't do too much, but had a couple of commitments each week, the Staff/Student committee, for example). 7pm - Usually go to formal, bottle of wine, Cindies or hours of drunken JCR fun.
Weds - Lectures [hungover], very rarely missed. Lunch. 1pm - Library until hall, possible afternoon lull if hangover returns. 8pm-1am - read again, probably bored with the subject by now
Thursday - probably no lectures, start planning and writing essay. Afternoon: may have computer class/supervision/practical etc. 6pm - Hall. Evening: This will either be a steady essay finish and a film, or an essay crisis until 3am. You can never really tell.
Friday - Hopefully have essay finished. Print off. Hand in, Go to maybe just 1 morning lecture. Go and pick up some reading for the next supervision, or do some work for a practical bit of coursework/dissertation etc. I usually tried to squeeze in some afternoon sport if possible on a Friday, then maybe a bit more work in the evening, but more likely lazing around and going out/bop if enough people were keen.
Saturday - Continue with the work as of yesterday. However, on quiet weeks a lot of Saturday was wasted through turning out for the college 2nd XI football/hockey teams and finding general reasons to waste time. In really busy weeks though, these fell by the way-side to an extent. Spent Sturday evening in the bar/out for dinner most weekends, but again, not always.
Sunday - Had a bit of a mantra I would never work Sunday mornings, which I think is a good idea. I recall working about 2 sunday mornings my whole 3 years. Usually, this was a lie-in til 10am, then play Mixed LAX, then brunch. Uber lie-in if no LAX. Sunday afternoon usually quiet too, possibly finishing reading or c/wk type stuff, could be more sport though.
One thing I would say is that Sunday evenings on busy weeks (especially with 2 supervision deadlines) could be fantastic essay crises, and you have to be prepared to stay up most of the night a few times. Other nights though, bar and bed by 1am.
I would like to think that is a pretty honest Artists week. As for Scientists, their added structure and number of deadlines means they did seem to have *more* work, although with the Artist workload you could always do more, even when you'd read enough, and some people did.
Anyway, from my experience, that weekly routine is not just enough to pass (far from it...) and led to a pretty good balance. I couldn't have done much more extra-curricular, but some people can so fair play if so. Don't expect much more than 6hrs sleep a night (my ideal...), but you're probably over-doing it if you get less than that regularly. As for supervision work, the Cambridge Wiki is really rational; don't exaggerate it, treat it as learning for good, punchy exam answers.
Oh, and you do more work at Cambridge than for a Newcastle MSc, but not by as much as some people would guess (though the fact it's a Masters probably makes the comparison less extreme). Cambridge is managable, just be realistic between the two extremes.
(P.S) apologies if the tense in the above is confusing as hell...