Can anything be truly permanent? Come, let us sit and discuss the metaphysics of change and permanence. Perhaps we will consider Heraclitus before moving to the eastern schools of philosophy.
Nah. I'm just going to talk about guitar stuff wearing out.
Nothing lasts forever
Everything wears out.
And one thing that wears out is the Graphtech String Saver guitar saddle. These saddles are softer than regular steel saddles and, as they wear, the strings can dig in more and more and may cause weird problems.
Chief among these problems is a buzz. You might hear a nasty zither-type effect because the string doesn't have enough clearance at the saddle. The string actually vibrates against the front of the saddle.
As the saddles wear under the wound strings, you may find indentations of the windings (which can't be great for tuning no matter how much PTFE is in the saddle).
Those saddles that you sometimes get on the Deluxe Strats and Teles—the ones with the small Graphtech String Saver insert in the steel saddle can also be problematic. The String Saver material can 'mushroom' out of the steel housing and give nasty zinging or string-deadening effects.
Now, it's fair to say that even steel saddles can, and will wear. And if you like the tone, and find the tuning improvement/string breakage claims to be worthwhile, you should have absolutely no hesitation in using the Graphtech String Savers. I'm definitely not here to tell you not to use them.
Do keep an eye on them, though. Give them a once-over when you change strings and be prepared to change them if you see (or more importantly, hear) any problems.