yospaghetti

Useful.

I did it for L1 and found that it was good to get used to taking a test in a crowded room and in an uncomfortable chair (as opposed to studying in my conference room where it is dead quite).

In terms of the difficulty level, I found the live mock harder than the take home practice exams and harder than the actual test (the later is likely due to the fact that I didn't do well on the Live Mock which kicked my ass into study mode).

If nothing else, its good to see the same questions asked in as many different ways as possible.