I'm a psychology student at the university of Zurich and member of the "Fachverein der Psychologiestudenten" (FAPS) and would say the following about Psych in Zurich assuming one does a normal degree from start to finish:
Pro:

• There is a lot of research going on, in particular in the Neuroscience area, where we have some outstanding people.
• You will in part be taught by people who are some of the best-known academics in their field.
• The area of study is very broad, you start with two-three years of "overview" and then decide what you do (so-called "Vertiefung")
• Most professors have well-prepared lectures with slides available for download.
• As a student you have access to many great facilities and the food in the student cantine is pretty good and value for money.
• There is no numerus clausus, foreign students are, however, asked to take an entry exam depending on what they did before.
• The FAPS runs a script group, whereby you take notes for one lecture per term and have access to all the notes the other people took in that term. Great for people like me who have to work.
• The fees are comparatively low, costing around CHF 1500 per annum plus about 200 - 300 Francs for books per term.

Contra:

• There is no numerus clausus, meaning that, on average, 700 - 800 people start psychology every year. The largest lecture theatre is set out for around 500 people and there are no podcasts available so if you need to hear the professor, you have to turn up early.
• A lot of the students are only just twenty and the Swiss school system seems to favour an attitude whereby you talk during lectures because you are still geared into thinking you HAVE to be there. Very annoying.
• Because there are too many people, you have to write exams at the end of each of the first two years. They have a pre-determined fail-rate of between 60 and 65% and you can re-take after one year. If you're unlucky like me, this can make you take four years to pass the first two years, whereby the first year is a reflection of how hard you work and the second is due to a lot of hard work AND luck.
• All the lectures are held in German only, some (but not all) of the books that must be read are in English. The lecturers tend to disagree with what it says in the books so beware...
• There are no grants or student loans available so you'll have to finance it all by yourself. You also have to find your own accommodation, which is costly.
• You are OBLIGED to take minor subjects and follow their demands, so e.g. English as a first minor will require taking a seven hour per week Latin course (unless you have a Latin A-Level or similar), as a second minor that is waived. You have to pick a first and a second minor and fit those courses in with the rest.
• The above may not seem as a disadvantage but the Psychology institute has recently been moved to Oerlikon, whereas most of your minor subjects will be in Irchel (near Milchbuck) or the Centre. The timetable means you will be leaving lectures early and arriving at others late.
• Some of the professors have openly said that they can't be bothered to teach and treat you accordingly. Or they will say that they can't understand how anyone can fail the exams, which is a bit harsh considering the pre-determined fail-quota.
• The department of Psychology is incredibly disorganised, with lecture times changing as late as a week before term starts. In some cases documents have gone missing etc. Other departments have the same issues, most students would tell you that the university would have failed if it was a company in the private sector.
• You will be made to feel that the university doesn't really want you there until you reach the latter part of your course. Having been accepted to a good University in the UK, this is one of the things I found hardest to deal with when I came here. Thankfully the FAPS takes some of the edge off by providing knowledge and support through the admin jungle.
• The exams you have to write will have mistakes in them or answers that are completely against what you learnt. Even though they decide on your future, the lecturers don't even proof-read what they set as an exam for hundreds of people. For example, I wrote an exam last summer where six out of 33 questions couldn't be taken into account because they were misspelled, had crosses next to the right answers in some of the versions etc.

That's all I can think of now and I realise there are more "against" than "for". It's just that studying here is VERY different from studying abroad and I would not want someone to come here with false preconceptions. Maybe my own opinion is particularly negative because I see behind the scenes. I'd be happy to hear a more positive view, as it may change mine...