If you replace one of your DVRs with the Genie, you can pretty much do what you are currently doing with the Genie having 5 tuners rather than the 2 your current DVR has. You do get a common/shared play list (via whole-home), but you don't get a common to-do list. The biggest problem with this setup is if you schedule a recording from the DVR, you can only schedule it to record on the DVR and if you schedule it from the Genie, you can only schedule it to record on the Genie.
If you replace your entire setup with a Genie and a receiver (not client), you get two video streams, either unit can see recordings from the Genie, and you can schedule recordings on the Genie from either unit. Plus, the receiver has it's own tuner so it doesn't use one of the Genie tuners for live viewing. The receiver should be able to be set to alternate IR codes.
If you replace your entire setup with a Genie and a client, you get two video streams, common playlist and todo list, but I think you have the problem of not being able to set different/unique IR codes.
The recurring monthly cost is identical for all three options.
So whichever of those scenarios gets you closest to what you want is what you should consider pursuing.