I have an older 1/2 keg that I ferment 12.5 gallon batches in. I siphon into corny kegs.
So cooling that much, bigger brew kettle, moving half kegs around to me adds a lot to brew day.
I broke an old washer down to the plastic tub, ran a pvc pipe up center and used pump to power it. It's pretty big though. Washes my sanke and corny kegs.