I believe there was a post here from a Kaplan rep recently and she/he stated that either (sorry, forgot which

, all the tests pool from the same pool, so one CAT wouldn't be any harder than another CAT except as would appear naturally by random luck from pulling questions, OR each CAT had its own pool but which CAT you receive at any time is random.
In any event, the net result is that you can't say that CAT 2 is harder than CAT4, or whatever.
Tom
fstep
i'm talking about the online ones, i've taken 5 so far and my results are just all over the place:
Cat 1 - 580
Cat 2 - 590
Cat 3 - 670
Cat 4 - 540
Cat 5 - 680
i took these all 1 week apart so it's not like i had that much time to study in between. so just wondering are these all supposed to be equally hard or does kaplan do this to jolt your nerves or something but making you either worried or excited every week?