Yes - thanks Pat, the carbon fiber is what I was referring to, and thanks for the detailed answer. Now since I confused gutitar hacker with my question and he asked if I mean " robo tuner pegs or the ones that work from the bridge with tension" - well - what about these 2 items. What are people's feelings about the need to invest in these 2 items.
I will say I HATE when my guitars go out of tune - and it happens way more to me than it should to somebody so serious about the study of guitar ha ha
Robotuners =
https://www.youtube.com/watch?v=Z6BY-JpAwgo on a Gibson
EVERTUNE =
https://www.youtube.com/watch?v=uttbIIhrL0o search evertune in youtube.... lots of videos there to watch.
If your guitar is a good quality guitar and you have good strings on it and it's set up properly for intonation...... it should hold it's tune really well. I have played many a gig and tuned up before the gig, and of course I check the tuning periodically through out but, in most cases, the tuning stayed dead on all night.
If you are having issues, you might wish to examine your hand technique since that can easily put a guitar out of tune or make it seem so. If you have a heavy hand, it's easy to be pulling the strings when you chord and that makes the strings, or some of them, go sharp.
One of the guitars I played with through the years had this issue. He had a really nice strat and would tune it with a strobe tuner. In the first song it sounded out of tune.... he'd check the tuning... perfect... He complained about the guitar.... had it checked, nothing helped. One night he commented that my SG kept perfect tune. We swapped for a set. Suddenly, he was having tuning issues with my SG. It turned out to be his hand technique. Something that only he could fix.