hi, i have had both knees done. My understanding is that if your hip needs doing as well, they prefer to do that first, so it sounds like your hip isnt as bad.
my forst one was more successful than the second one.
I have NEVER been able to kneel post-op, but i dont think that's too unusual. For both of them, immediate recovery was quite short - days before i could go on outdoor walks, six weeks till i could drive,
six months before it felt "normal" ie that i didnt have someone else's leg attached to me! climbing stairs was almost immediately easier than pre op.
the second knee has much less flex in it. I was offered serial casting, in order to increase the straightness my leg could do. I declined because at the time i had had 2 babies, 1 hip replacement and 2 knee replacements within about 18 months and i was utterly fed up of seeing the hospital and couldnt bear the thought of going there every week. My knee was 85% better than pre-op, and i could live with the loss of movement in it