In the lab environment provided for the exam, we will have access to tools such as vSphere Client, mstsc, putty, etc....the latency is quite high if vCenter is accessed by opening an rdp session to Windows as opposed to accessing it directly via the vSphere Client. So again if you are facing latency issues in the exam try to access the vCenter using the vSphere client directly.
I lost crucial minutes due to this and was able to complete only 4-5 questions in the first hour. I had reviewed the questions I left out before the timeout and I could have easily attempt some of them if I had time. Nevertheless I got my results today and was able to clear the exam with a slight margin so it's behind me now but wanted to highlight it in the forum so it helps the next aspirants. There are ample resources on the net and good threads on this forum for the preparation so I have got nothing more to add on it..
Also want to take this opportunity to thank the certification team for their understanding and support while I was facing scheduling difficulties....
Best of luck!!