What do you want? Here is my recent experience and I got everything I wanted and more.
There is one exception. If you want to upgrade your HR20-700s to the latest model, the HR24, that might be tough to do through DirecTV. DirecTV considers all DVRs equal. If you wanted to upgrade, you'd have to do that through a independent retailer like Solid Signal, which would cost you money.
I'm not sure you'd really want to get rid of your HR20s, though. All of your recordings on your 1T drives would be lost.
There is one exception. If you want to upgrade your HR20-700s to the latest model, the HR24, that might be tough to do through DirecTV. DirecTV considers all DVRs equal. If you wanted to upgrade, you'd have to do that through a independent retailer like Solid Signal, which would cost you money.
I'm not sure you'd really want to get rid of your HR20s, though. All of your recordings on your 1T drives would be lost.