Single-dish of this size has great sensitivity: it's a huge photon bucket. It doesn't need a long time on-source to make an image. So it is "FAST".
A telescope array is basically a huge structure with lots of holes in it. As the Earth rotates, the elements of the array sweep out arcs. That fills in some gaps. So even with a relatively bright source, you might need to wait a while before you fill in enough to be able to discern the details. So a big, single dish is "FAST".
Array elements are spread over thousands of meters. You get great resolution, like a microscope on the sky. But you also get all these diffraction patterns. Since you know the shape of your array, you can mostly solve for this, but it's a pain in the ass.
A telescope array is basically a huge structure with lots of holes in it. As the Earth rotates, the elements of the array sweep out arcs. That fills in some gaps. So even with a relatively bright source, you might need to wait a while before you fill in enough to be able to discern the details. So a big, single dish is "FAST".
Array elements are spread over thousands of meters. You get great resolution, like a microscope on the sky. But you also get all these diffraction patterns. Since you know the shape of your array, you can mostly solve for this, but it's a pain in the ass.