I don't use continuous assessment in the place where I'm currently working, since grades are based on the exam due to the nature of the program and the kind of ss I'm working with.
Nonetheless, I consider continuous assessment quite useful and it is my view that it is not difficult to grade like that, it is more a matter of getting orgnized with the evidence or so.
Continuous assessment provides with a clear image of the ss' progress and since activities are carried out under class conditions - a more relaxed environment compared to the exam conditions where everyone's nervous - therefore, ss are more likely to make less mistakes and show how much they've really progressed. On the other hand, continuous assessment provides as well with evidence that exam do not, such as: ss' commitment, efford, perseverance and so forth.
I think continuous assessment creates more work for disorganized people, but if the T is an organized person, continuous assessment should be easy to carry out.