Well, we'd need a real professor to explain the Finnish educational system, but I'll shed some light on your thirsty minds.
Here in Finland we have many kinds of these polytechnics - for example, I study youthwork in Humanities Polytechnic (and no, I won't become a human engineer). Theoretically, my studies are university-level studies, but in practice I have much easier time - and will get less salary once I have finished my studies. The thing is that you can't study youthwork at university in Finland, but if I were in university I'd need to study something like social-work to do the kind of work I will do.
But if I studied to be an engineer in a polytechnic, it would probably be much harder than in university - and I think engineers gain more money as well. At least my soon-to-be-engineer friend gets already about 2000 euros a month - and he's still studying!
But as I'm not that greedy a person anyway, this polytechnic and its studies suit me fine - I think I will survive with 1200 euros a month the rest of my life.
-Villain
EDIT: About the times, my studies should take three and a half years (but they will probably take somewhat longer), whereas the university standard here is about 5 years, I think.