Attached are 2 screenshots showing an invoice being edited in the original interface and the same invoice in the new design. The original is very usable design with appropriate spacing for numerical values and description
In the new style screen - large gutters between cells leads to screen being much less readable. The description is now squashed and fields for numerical values too large to the extent that it only fits on the screen if viewed at 90% ...
Improving performance is good but if its at the expense of usability it doesn't actually help users.
In being asked to categorise this I'd say everything needs review, not a single area bit that's not an option so selected invoicing as my example is in that area.