I know its not a big sample since its only 30 questions, but I found the 1st CFAI sample much easier than any of the Book 6 tests.
Also for what it’s worth the CFAI end of chapter questions are a lot easier than Schweser.
Don’t know if the sample or end of chapter questions are representative of the real test though.
I do remember Level 1 being somewhat of a relief on exam day though. I walked out knowing I had passed after not being overly confident in my Schweser test performances