For my interstate move I had 2 "square" 20L Bacchus cubes for no chilling, full of wort. I rarely keep a cube for more than a week before pitching, nearly always the next day. These had been sitting for over a month and sadly they developed infections and started swelling so I chucked them - no point in courting disaster by putting further brews into them.
On arrival and setting up brewery I visited the LGS (edit: BGS) at Taree and they didn't have anything like a fresh wort cube, just the Willow variants that are great for 30 bottle brews but a bit too large for my keg only brews.
However they did have 10L "cubes" and on taking 2 home and doing a measured fill, when used as a NC cube they actually hold 11L. Perfect.
Advantages occur to me:
Surface to volume ratio means much faster cooling, especially in these climes where it can be 27 at noon but 9 at midnight at the moment.
Far easier to handle and glug into the fermenter
Cube #1 can be guaranteed to have pure clean wort, and due to easy handling Cube #2 can be more easily controlled on pouring to avoid any hot break going into the fermenter.
Brewing tomorrow, will report. About $14 each so not cheap but still in the "Willow" ballpark so not too bad.