Yeah, I started using that same protector a couple of months ago and I LOVE it.
I also have found that I like the feel of the contact better when I've worn the nib down -
and when I went to replace it the new one felt all slippery again.
Here's my current nib (Bottom, top is a fresh one):
I'm going to have to change it out at some point, but at least I know that it may take an adjustment period when I do!!