It sounds like DTV wants all their customers on the server/client model anyway. DTV hasn't made any new tuner based models in a long time. Its only new servers and client boxes.
So in the current server/client model you can't have all the clients on at the same time? How many can you use at the same time? Maybe in the new system they will change that so you can use them all at the same?
with a current genie you can have 3 clients viewing at a time (you can have up to 8 connected iirc)
with the hs17, its 7 viewing iirc
current genie 1 4k feed
hs17 2 4k feeds
current genie 5 tuners
hs17 7 tuners