Unity300 capacity question

Hello all, I have a Unity300-hybrid, and I am trying to determine actual space usage to find usable space remaining in my Unity, since there will be more storage migration from an older array onto this new array.

I see different allocated/used% number when I look at the LUNS in the Unity vs. what I am told from DATASTORES in VMware and I am trying to understand why the numbers don't match (example, why Unity thinks LUN1 is 55% used but VMware thinks it is 90% used).

Which numbers should I use to determine remaining capacity.

   Thank you.