Short advice: take some other ones. Like CCA 175, let you learn more.
Here is the long version.
I took the HDPCD in the early January 2018 twice. The experience is a nightmare!
First time, even I am warned by others in the forum that the window and keyboard are unmanageable, I am still shocked by the awkward experience I had to go through. The window is so small and connection lost for no reason (I have 50MBPS and never down network connection.) It is hard to move around or view the whole line. I almost gave up but managed to work for 2 hours. I am sure that I failed at that time.
After finished, I rethink the whole exam and how I failed. I felt that the material is not hard, that may be the reason they made the interface hard to test your patient, which is not stated in the objectives. I felt that if just open two windows, work from there I should pass. So I took the exam again after four days. I only opened two windows and verified all my results. I am sure I passed the exam because I verify all the results in different methods.