Thank you for your post.
The PP264 and PP218 are essentially the same although the PP264 is a slight improvement upon the PP218. Unfortunately I do not have any specification details as to how these are different.
I am also unable to supply specific figures as to rise/fall time, noise, or influence of adjacent items.
The clamp can measure currents as low as 10mA, and this is independant of voltage and frequency.
Hope this helps