Two years ago I took my step one and I scored 96. I was reading Kaplan Notes and also doing Kaplan qbank only.
Somebody gifted me the Step-Up for USMLE Step 1. I did not want to read it because nobody was talking about it.
But then I opened it in my spare times and at bed time.
I noticed that's it's a great book. It had very nice organized high yield information. So I read it all and it was my primary review book. It can replace your first aid.
But, it's a review book only. If you are a grad you need to read some more detailed review before such as Kaplan notes then you use this book as a review only. Don't read it alone.