1. OTA is important if DTV does not provide all stations in an area. This has been the case so far. If DTV can provide all locals for all areas then it will not be an issue. 2. Are the HR21s specs for resolution and signal sensitvity the same as the HR20-700s? It seems that the HR20-100 is more sensitive than the HR20-700 for off the air and perhaps sat. 1080p upconversion would be nice if the HR21 can do that.