I bought two commercial mock exams (softSCBCD and Whizlabs SCBCD) but, unfortunately, I was too short of time to use them as I'd have to. I couldn't try more than 2 out of 5 softSCBD mock exams and just 1 out of the 5 from Whizlabs. Both products seem helpful though.
So, yes they may be useful, but OTOH I proved that you can pass without them. If I had to start again, I'd just buy one of them, probably softSCBCD (which is OK and cheaper). Whizlabs SCBCD looks OK too, but it's so different from the real exam (fill-in-the-blanks questions don't exist on the real exam) that I found it more as a trainer than a mock exam. The best mock exam IMO is the final one you find in K&B book. It's very close the real one, though a bit harsher. I passed it a few hours before the real exam and got 87% with it (in comparison with 94% on the real one), but taking 4 mistakes in the exam into account (I mean that my "official" mock score was worst and that I had to correct it ). Best regards, Phil. [ December 20, 2003: Message edited by: Philippe Maquet ]