I guess one has to get two 721's instead of one 522. You can get two 721's now for less than what one 721 cost when it first came out. You do not get charged the DVR fee and no additional outlet fee on the second tuner. Having two 721's would allow you to get more events recorded or to watch a show while an event is recording vs. having one 522 although you would get charged the additional outlet fee on tuner one for the second 721. You would also have twice the recording time. One 522 would cost $350 vs. $500 for two 721's. I think the better interface, extra two tuners and additional recording space is worth the extra money.