I agree. I felt so dejected after taking the Kaplan full length. I wasn't happy with my % and wondered what the heck I had been studying for last weeks. But I was happy with my NBME 1 week before real thing and definitely felt the real thing was more realistic. (excluding the "what the crap?!" questions on the real thing)
That being said, I learned a lot from Kaplan questions in general. Yes, they are more detailed and seem to require more thought, but I finally realized the reason was for us to LEARN from them. That's what we paid the big bucks for.