Harder vs. Easier LSAT PrepTests

I can't tell between a "harder" or "easier" LSAT PrepTest. All I know is that people find something to complain about after each actual LSAT test administration. They'll say it was harder than all the previous PrepTests they've taken, due to ____ (hard Reading Comp passage / hard Logic Game / several hard Logical Reasoning questions).

Personally, my guess is that some people just feel like their actual PrepTests are harder because it's the real thing, and adrenaline's pumping. Also, if they don't take their practice PTs under realistic (strict) conditions, LSAT Test Day may seem much harder by comparison.

One more thing: there may be some selection bias at play - people who don't find their actual LSAT test administration harder may not go online to complain about it afterwards. They're off having fun and taking a much-needed break from LSAT stuff.