After a solid weekend of doing questions...I have more and more come to agree with this.
The authors of the portal should really be ashamed. The quality is incredibly poor. Probably on average 1/10 questions where either the answer choice is incorrect or mislabeled (i.e a "all of the following are true except..." question stem, then the answer is actually the correct one, not the incorrect). Most references are from the mid-90's.
Some of the questions themselves are ludicrously minute (even compared to the ABSITE).
They really should add a "report a problem with this question" feature so that they can get these corrected.