This is true if you're absolutely unwilling to try OTA.I have a 722k but do not use it in Dual Mode as I like the flexibility of recording a show and simultaneously viewing another. If I set it up in dual mode the second tv would be limited to the recording.
In Ira's case, there are five programs simultaneously and you probably can't watch all of them live. I'm assuming that at least two of them are available OTA.
I'm thinking that a single ViP722K could output two live programs (while recordign them) and record two with an OTA module and a serviceable OTA antenna. I'm assuming that SD viewing is not a show stopper. If you want HD, you can go back later and watch it in HD.
The 625 is limited to two programs and there's no confusion about dual mode versus single mode.
I can record four programs at once with a ViP622 and a 508 so I'm thinking that spending the extra on a discreet OTA setup would be better than leasing another DVR.