Just passed the HPE3-U01 exam yesterday. Honestly first attempt was a mess because I was just reading through Aruba docs without actually testing myself on anything. Wasted weeks doing that.
Then I started using itexamstopics.com exam topic-wise questions and it was night and day. Actually doing practice questions instead of just reading made everything stick. Studied properly for two weeks with their practice tests, retook it, and passed easily. If you're prepping for this, skip the reading phase and just jump into practice questions from the start. Saves so much time.