Is Prep Scholor/College Simply good?

Straight forward. Is prep scholar and/or college simply have accurate good data for GPA’s etc? They seem a lot lower that what I think…

Anyone???

They were overly optimistic for D16 and admissions have just got harder since.

Ok anyone else??

The closest thing to an authoritative source for GPA and test score data is each school’s Common Data Set, Section C, which you can look up easily in case you doubt the PS or CS numbers.
Example:
According to the University of Maryland College Park 2015-16 CDS, the average GPA for entering freshmen was 4.22.
Prepscholar reports the same number.

However, a few colleges don’t publish a CDS. Many others do not include GPA averages in their CDS. In those cases, I’m not sure where PS or CS get their information.

Even if the numbers are reported accurately, you should not necessarily take them at face value.
According to Princeton’s 2015-16 CDS, the average HS GPA of entering freshmen was 3.90.
However, Princeton may be using a different formula to calculate GPA than UM-CP uses.
Or, Princeton may be admitting a higher percentage of students from rigorous programs at very competitive high schools.

(In other words, GPA reporting is not “straightforward”.)