Hi Fadi,  Looking at the screenshots you sent - Datastore Performance averages your individual datastore/host performance metrics. So, by using Datastore Performance, you're getting the full picture of what's going on with that datastore. Considering some of the individual performances in the Current Bottlenecks tab, you may/may not want to look in to storage vMotioning any of the heavy hitting VM's.
Hi Team,  I am currently in the process of investigating whether there are any storage performance issues in our current VMware environment. What I would like is a simple report showing a graphical representation of storage latency over a 24/48 hour period.  The home screen dashboard shows "75 Datastores have been experiencing high-latency issues over the past 24 hours". This is common at each logon and can increase to over 200 datastores with issues. Looking at the Performance/ Current Bottlenecks/ Latency tabs it shows total peak for many datastores at about 800ms. This looks to be a major storage performance latency problem in our environment. However, looking at the Performance/ Datastore Performance tab the average and peak latency is way below this value.  Is there something I am missing?   
Storage Latency