This mod addresses some vanilla container UI issues.

Grid is tiny. 3x5 default grid means you need to rescale it by dragging small scale button every time you open one of your bags. With this mod default grid is 6x7 (or 5x5 if you prefer middle ground), 8x9 is also available.
"Sorting options" button is a weird joke. No point to hide sorting behind this button if you can give access to it right away. With mod "sorting options" is gone for good, you have access to sorting and inventory toggle button from the start.
When you are instinctively trying to drag window by grabbing its upper part of panel, you click on forementioned "sorting options" button instead. All other panel parts are not especially convenient for grabbing. Mod makes room in upper part of the panel for dragging.
Game is trying to render container's panel over container's model. That means once you started scaling it you can't see character and container anymore. Also when you summon inventory panel container will always overlap it. Mod will render panel to the right of container and slightly lower (not always, mind it, only if UI space is enough), trying to make container's items ready for drag and dropping to inventory panel when you call it.
On max height scale container's scale button leaves panel space. Scale button in the right bottom corner will stick to panel space (with a cost of minus one row of max height tho).
Container name, content's weight and value in gold added. May come in handy for evaluating loot containers.

Better Containers