Note you can only pause up to the buffer size, which on HD DVRs is 1 hr. After that it will go live with a buffer filling as the oldest part is "erased". The same duration, not bytes, buffer for SD or HD.
But when you "unfreeze", it jumps back to live action, doesn't it? I wouldn't compare it to a DVR pause, because on the DVR, you can pause, go to the bathroom or something, come back and continue where you left off. A "freeze" feature doesn't give you that.