Yes, getting adjusted to the new GUI is not something straight forward, have struggled as well. But, with time, you will get adjusted.
Try these commands:
::> vol show -percent-used > 97
::> df -h true -available-space >1TB
::> df -h true -available-space >=1TB
::> df -h true -available-space <=1TB
Also, if you have a OCUM/AIQM: That would be much easier and simpler to work with filters.