You simply do not understand. Your current subscription would be cancelled but would need to be redone and then you would be given the $20 credit so that you would not have to pay the $59.95 rate. Looks like a simple technicality to solve what you want. The extra 2 devices is a real plus.
HD signals for HBO is certainly needed and must be done correctly. I have patience but some do not. This is not a concern for me.