My experience with errors on FiOS is very channel dependent. E.g. right now channel 502 KATU, frequency 513 MHz, has no RS corrected or uncorrected. But channel 780 Disney, frequency 327 MHz, has a few RS uncorrected and many many corrected. Detailed info: channel 502, 37 dB, 0 uncorrrected, 0 corrected, 475 seconds. channel 780, 34 dB, 13 uncorrected, 1,390,000 corrected, 490 seconds. The one with errors is national, the one without is local. Which probably means the two blocks of channels are being combined by Verizon locally. But even on the channel with reported errors, they occur infrequently enough that as a "casual" viewer I haven't noticed them in the program itself. I haven't experimented with adding attenuators or diplexers, but I may try them just to see if I can get the error count to decrease.