Such measurements are providing a powerful probe of the early universe. They can discriminate between competing cosmological models and have already ruled out some specific topological defect models. We are analyzing data from the 1998 flight, and plan to publish results very soon.
Raw sensitivity is only one aspect of an effective CMB anisotropy measurement.
Systematic errors must be minimized by the scan strategy of the experiment. These two scans occur at different angles, due to the earth's rotation, producing a cross-hatched pattern. The data are proving to be of high quality. We have produced maps of the sky from several different array elements and these maps show consistent structure from one to another. We have produced preliminary angular power spectra and are performing a battery of tests for systematic errors.