Having encountered quite a bit of handwritten Japanese during my stay here, FW, I would have to say that it is probably more like half and half. I think it may depend a lot on the age and education of the person doing the writing.
The nature of my work has me coming in at about 3 o'clock in the morning and finding notes from my boss on my day's assignment. My previous boss has a cursive hand that is quite nice to look at....but which can be tough to read sometimes. His son, who currently fills the position, similarly writes his notes in a cursive hand, retaining the sometimes difficult to read aspect while unfortunately lacking the saving grace of looking pleasingly graceful.
It takes a little while as a foreign learner to pick up on reading handwritten Japanese, as it can appear quite different from printed fonts. Further, there are some common shortcuts in handwritten text that all native speakers seem to know from long acquaintance, but which to the foreign learner may look like a different (and unknown) character.
I remember one particular morning standing baffled for quite a while trying to figure out where the heck 下井 is and why I would be sent there. I finally figured out it actually said 大井, which is a place I go to several times each week.
I would suggest that beginners not even bother looking at handwritten Japanese until they get a firm grasp of all the kana and a little familiarity with printed writing. I say that for the simple reason that getting a look at some really stylized cursive text too early on, before one has enough time and effort invested in learning Japanese to give up easily, could discourage one to the point of despair.
