For crunchy texture, pick when it just transitions from darker green to a lighter green. It will be lightly sweet, but refreshing.
If you let it go longer (even lighter green with red streaks), it will be even sweeter, but lose a lot of it’s crunchiness.
Right now, I would consider your fruit in the picture as ready to pick for good crunchy texture with light sweetness.
You must be experiencing a later crop, as most of my crystals were gone well over a month ago.
Here are pics of moderate crunchy, moderate sweet (overripe to Xue):