Spring behaviour

[Phillip Ford]

>    The major benefit of the Renner whippens is
> that their teflon adjustment 
> screw provides a VERY long lasting spring
> regulation. ( I have numerous 
> actions at the school where the spring adj. has
> been stable for years).  
> Regards, 
> Ed Foote RPT 

Ed,
I much prefer this adjustment to the easing, warming, rubbing, bending,
mangling (choose your word) that serves for regulation of the Steinway style
spring.  But I don't have long term experience with these.  I've heard that
some manufacturers (sorry, I don't remember brands and I don't remember the
source) had switched to these and then switched back for two reasons:
1.  The teflon adjuster and wire interaction develops some noise over time.
2.  Repetition is faster with the Steinway style spring than with the teflon
adjuster style.

Have you found either of these things to be the case?

Phil F