I've noticed with Apple+, I cannot get good recordings in FullHD. The video is choppy, however, if I drop down to HD, the recordings are fine. I've noticed other users experience this same behavior.
Note, on my system, other channels (i.e. Netflix) record fine at the higher level, so I'd rather not drop down quality on those recordings.
It would be a nice feature to be able to set the video quality at the channel level, rather than for ALL recordings.