I'm cautious by nature and prefer to run my larger aquariums lean on bioload, heavy on filtration, with sufficient backup equipment to have multiple options should a problem arise, as well as keeping a smaller backup tank up and running for each larger tank to allow for quarantine of new stock, grow-out/quarantine of new plants, etc. This burden--in equipment, space and care requirements--works to greatly limit my tech laden tanks.
The joys of no-tech planted vases, however, led me a bit astray. When a new habitat takes less than a week to set up, can be placed anywhere there's light, stocked and planted entirely from existing populations? Mayhem. At the highest point I had 40 scattered throughout my tiny apartment--in addition to my 37g, 20g, 10g, and 2x 2.5g standard tanks. They taught me a great deal, and it was tremendous fun to experiment with them, but I've been steadily (sometimes painfully) whittling their numbers down. Current count is 15 bodies of inhabited water, with an ultimate goal of 9.