OPEX would be about 20-30% cheaper for me
What exactly are you comparing?
I'm in a densely populated, high electric cost area. The tanks would look much better if I lived, say, in Washington state.
If you are in a densely populated area 6 tanks with 1.2MW total would take a lot less space than dozens of racks?
And in a place like Washington with $0.02/kWh cooling would be relatively small, no matter you pay a lot or a little?