What are your experiences with tweaking anchor texts?

According to this artice, changing the anchor text of a backlink will make google trust it less. What are your experiences with this? I changed some anchor texts foolishly before reading the article, and now I think I may be wasting my PBN links because Google could have devalued them, but I don't know for sure. Have any of you noticed links becoming weaker, or completely devalued from changing the anchor…

What are your experiences with tweaking anchor texts?