Totally depends on what you’re trying to do. Arecibo was used in transmit mode, too, for studying asteroids, etc. and the “thinned array curse” hits you hard if you don’t have a filled array for transmission as most of your energy ends up in sidelobes, not the central beam.

Plus, sparse array only works well for high contrast, high brightness sources. And it has a bunch of artifacts that can get in the way of interpretation of the data. Plus just pure filled area matters a lot.