Do you know of many FTA receivers that record more than two channels?
I suspect that many of the DVRs that you're comparing against are designed as whole-home configurations housing the household's compliment of tuners in fewer, much more costly, DVRs with clients for a majority of the TVs. Since Orby doesn't support whole-home and their channel count is typically not as high as most other pay TV services, two tuners per TV perhaps isn't a hardship. Orby obviously trades on being a good value rather than being the technology leader.