Anyone with experience of such stairs?
http://www.trappfabriken.se/trappor.asp?ProductID=19
http://www.trappfabriken.se/trappor.asp?ProductID=19
I have a friend who has a similar one, but it's not straight; instead, it's a spiral staircase all the way up. I hate it. Very difficult to walk in, very cramped, and completely hopeless when you have something in your hands, but he and his family like it, so it's not my headache 
I have tested the spiral version a bit, and I agree with ktm. It is way too tight, and in my opinion, a much too flimsy construction. It feels cheap.
The spiral staircase, however, is not interesting, but the 89cm wide L-staircase. However, I'm leaning towards making my own staircase.