If you love your knees, pick up a good set of knee pads. I had these included with my 1X pads and I love them. I've had a number of shots get through to the knees and haven't felt a thing and they feel great when going down into butterfly.
The straps hold nicely and have a bit of adjustable area, but they will, as with most knee pads, slip around a bit. So, if you find that happening, consider picking up a garter belt, if they don't come with one.